[Event "Soviet ch Moscow"]
[Site "?"]
[Date "1973.??.??"]
[Round "?"]
[White "Beliavsky, Alexander"]
[Black "Spassky, Boris"]
[Result "0-1"]
[Annotator "JvR"]
[SetUp "1"]
[FEN "r3k2r/3bb2p/p3pp2/n2p4/3N3B/8/PPP3PP/2KR1B1R b kq - 0 18"]
[PlyCount "57"]
[EventDate "1973.??.??"]

{Advanced strategy in the endgame by Jan van Reek.  Lesson 1: An attack in the
centre.   Strategy in the endgame can be simple. I consider a usual situation.
One player seeks the struggle by moving the pieces forwards and another person
reacts to the attack. Such uncomplicated strategies of struggle will be
treated in several lessons. Difficult strategies will be discussed later. An
attack in the centre is a very simple strategy. The successful advance of
centre pawns has been shown by Philidor.   This example is more recent. Black
has a broad pawn centre. He can start a direct attack, if he advances the
pawns properly and uses the pieces for support.} 18... e5 19. Nb3 Nxb3+ 20.
axb3 Be6 21. Be2 O-O 22. Rhf1 a5 23. Bb5 {The bishop prevents ..a4.} 23... Rac8
24. Bd3 Rc6 25. Bf5 ({Kotov prefers} 25. Kd2 {
in order to play Ra1. However, Black can play ..e4 and ..d4 in that case.})
25... Bxf5 26. Rxf5 Rfc8 $1 27. Rd2 d4 {Black threatens ..d3.} 28. Kd1 $6 ({
Slightly better is} 28. Kb1 $5 {
although this move gives less protection to an advance in the centre.}) 28...
Rb8 $1 {The threat ..a4 decides the game.} 29. g4 h6 30. Rdf2 Rbb6 31. Kd2 a4
$1 32. bxa4 Rxb2 33. Kd3 Kg7 34. Rxe5 $5 {A sacrifice brings the last chance.}
34... fxe5 35. Bxe7 Rc3+ 36. Ke4 d3 $2 (36... Re3+ 37. Kd5 d3 38. Ke6 dxc2 {
Black wins, because White has no drawing mechanism.}) 37. Bf6+ $2 ({
Coincidences contribute to the great escape} 37. Bd6 $1 Kg6 $1 (37... dxc2 38.
Bxe5+) 38. Rf6+ $3 Kxf6 39. Bxe5+ Kg5 40. Bxc3 Rxc2 41. Kxd3 Rxh2 42. a5 Kxg4 {
White narrowly draws.} 43. Kc4 h5 44. a6 h4 45. Kb5 Re2 46. a7 Re8 47. Kc6 h3
48. Be5 $1 {Spassky didn't know this combination. "You were lucky" I teased
him. He nodded with a smile.}) 37... Kg8 38. Bxe5 Rb4+ 39. Kd5 Rxc2 40. Rf1 d2
41. Rd1 Rxg4 42. a5 Ra4 43. a6 $1 Kh7 (43... Rxa6 $2 44. Bf4 $1 Raa2 45. Bxh6 {
(Kotov).}) 44. Bb8 Ra1 $1 45. a7 Rxd1 46. a8=Q Re1 {
Black's strategy in the centre has led to a complete success.} 0-1

[Event "Linares"]
[Site "?"]
[Date "1999.??.??"]
[Round "10"]
[White "Anand, Viswanathan"]
[Black "Kasparov, Gary"]
[Result "0-1"]
[Annotator "JvR"]
[SetUp "1"]
[FEN "8/8/4b3/p1n5/N4k2/K1P5/2P5/8 b - - 0 36"]
[PlyCount "29"]
[EventDate "1999.??.??"]

{Lesson two: The attack on the king.   The final aim of the attacker is to
mate the opponent. Nevertheless a mating attack rarely occurs in the practical
endgame, because an experienced player will resign before it can happen. The
attack on the king with few pieces often is a part of the basic theory. An
interesting direct attack on the king occurred in Linares 1999.} 36... Ne4 $2 (
{Correct is} 36... Nd7 $1 37. Nb2 Nb6 {Kasparov's analysis continues with} 38.
c4 Bxc4 $1 39. Nxc4 Nxc4+ 40. Kb3 Ne5 $1 41. Ka4 Nc6) 37. Nb2 $1 {
The defence of the c-pawns has little importance.} 37... Nxc3 38. Nd3+ Ke3 39.
Nc5 Bf5 40. Kb2 $1 {A potential defender of the a-pawn is chased away.} 40...
Nd5 {A protection by the king loses matter.} 41. Nb7 a4 42. c4 $1 Nb6 43. Nd6
Bd3 44. c5 $1 Nd5 45. Ka3 Bc2 46. Nb5 $1 Ne7 {
The knight has to stop the c-pawn.} 47. Na7 $2 ({
Anand could have crowned his wonderful defence with} 47. Nc3 $1 Kd4 48. Nxa4
Kc4 49. Nb6+ Kxc5 50. Nd7+) 47... Kd4 48. c6 Nd5 49. Nb5+ ({
My preference goes to} 49. Kb2 $1 Bf5 50. Nb5+ Kc5 51. Nc3 Nb6 52. Ka3 {
Black wins by} 52... Nc4+ $1 53. Ka2 (53. Kxa4 Bc2#) 53... Be6 $1 54. Nxa4+ Kb4
55. Nb2 Nd2+ 56. Ka1 Ka3 57. c7 Nb3+ 58. Kb1 Bf5+ 59. Nd3 Bxd3#) 49... Kc5 50.
c7 Bf5 $1 (50... Bf5 $1 51. Kxa4 (51. Na7 Nxc7 52. Kxa4 Kb6) 51... Nb6+ 52. Ka5
Nc4+ 53. Ka4 Bc2#) 0-1

[Event "Corus Wijk aan Zee"]
[Site "?"]
[Date "2000.??.??"]
[Round "1"]
[White "Korchnoi, Viktor"]
[Black "Kasparov, Gary"]
[Result "0-1"]
[Annotator "JvR"]
[SetUp "1"]
[FEN "8/pp2k2p/4p3/4n1p1/N3P3/1P1r4/P4P1P/2R1K3 b - - 0 35"]
[PlyCount "39"]
[EventDate "2000.??.??"]

{Lesson 3: The flank attack.   If the centre and kingside are secure, a direct
attack becomes too risky. Maybe a weakness can be found on the flank. If this
is the case, an indirect attack can be aimed on the weakness in the enemy line.
Both players threaten a flank in the example.} 35... Rd7 $2 (35... Kd6 {
increases the restriction. The black rook threatens to move to the h-file. The
pointe is} 36. Nc5 b6 $1 37. Nxd3 Nxd3+ 38. Kd2 Nxc1 39. Kxc1 Ke5 $19) 36. Ke2
Nd3 37. Rc3 Nf4+ 38. Kf3 Kf6 39. Nc5 Rc7 40. h4 $2 {
The last move under time pressure is a serious mistake.} ({The subtle variation
} 40. Ke3 $1 h5 41. f3 $1 {draws. After} 41... b6 42. Na4 Rxc3+ 43. Nxc3 Ke5
44. a3 Ng2+ {square f2 can be used by the king.} 45. Kf2 $1 {
The black knight cannot start making troubles.}) 40... e5 41. hxg5+ Kxg5 42.
Rc4 {Now the terrible effect of Korchnoi's blunder becomes apparent. The g-
and h-files can be used by black pieces. Black starts an irresistible flank
attack.} 42... b5 $6 {An immediate advance of the h-pawn is stronger.} 43. Rc1
b4 44. Rc4 a5 45. Na4 Rf7 $1 {
The rook is not exchanged but will support the h-pawn.} 46. Ke3 Ng2+ 47. Ke2
Nf4+ 48. Ke3 {White has no proper defence.} 48... h5 $1 49. Rc5 Ng2+ 50. Ke2 h4
$1 {Only the advanced pawn is important.} 51. Rxe5+ Kg4 52. Re8 (52. Rxa5 {
is useless.}) 52... Nf4+ 53. Ke3 h3 54. f3+ Kh4 {The h-pawn cannot be stopped.
The attacker does not seek the confrontation in an indirect attack, but avoids
the strongholds. The saying: "Many battles are decided by marching",
characterises this strategy.} 0-1

[Event "Wch Sevilla"]
[Site "?"]
[Date "1987.??.??"]
[Round "24"]
[White "Kasparov, Gary"]
[Black "Karpov, Anatoly"]
[Result "1-0"]
[Annotator "JvR"]
[SetUp "1"]
[FEN "5nk1/4q1p1/4p2p/1Q6/4B3/4P1P1/5P1P/6K1 w - - 0 42"]
[PlyCount "45"]
[EventDate "1987.??.??"]

{Lesson four. Encirclement.   A long siege of the opponent is best known from
middle games with a closed centre. The opponent is slowly crushed through the
flanks. Encirclement also occurs in the endgame. An interesting case is the
decisive game in Sevilla 1987. Kasparov trails by 11-12 and has to win the
adjourned game in order to keep the title.} 42. Kg2 {White is able to attack
with queen and bishop on the left flank. The h- and g-pawns can advance at the
other side.} 42... g6 $5 {Karpov enlarges his fortress, because he fears an
attack on the kingside. If a pawn is admitted to h5, an advance to g5 can
start.} 43. Qa5 Qg7 44. Qc5 Qf7 45. h4 h5 $6 ({Kasparov prefers} 45... Kg7 {
White will play} 46. g4 {and 47.g5. This allows an exchange on g5. Thereafter
a pawn advances to e5 and White will win anyway.}) 46. Qc6 Qe7 47. Bd3 Qf7 48.
Qd6 Kg7 49. e4 $1 Kg8 50. Bc4 Kg7 51. Qe5+ Kg8 {Black has to remain passive.} (
51... Qf6 52. Qc7+ Qf7 53. Qxf7+ Kxf7 54. e5 Nd7 55. f4 $18 {The bishop is
aimed at g6 and white's king marches to the queenside. The weaknesses e6 and
g6 are fatal for Black.}) 52. Qd6 Kg7 53. Bb5 Kg8 54. Bc6 Qa7 55. Qb4 $1 Qc7
56. Qb7 Qd8 ({Even} 56... Qxb7 57. Bxb7 e5 {does not save the game.}) 57. e5 $1
{The encirclement has been completed. Black misses a pawn on f7 dearly. White
conquers square f7 and thus penetrate the fortress.} 57... Qa5 (57... Qd3 58.
Be8 Qf5 59. Qf3 $1 {(Kasparov).}) 58. Be8 Qc5 59. Qf7+ Kh8 60. Ba4 Qd5+ 61. Kh2
Qc5 62. Bb3 Qc8 63. Bd1 Qc5 64. Kg2 {Black can only move his queen in the
final position. Karpov resigned and Kasparov kept the world title.} ({
Kasparov analyses} 64. Kg2 Qb4 65. Bf3 Qc5 66. Be4 Qb4 67. f3 $1 (67. Bxg6 $4
Nxg6 68. Qxg6 Qb7+ 69. Kh2 Qg2+ $1 70. Kxg2) 67... Qd2+ 68. Kh3 Qb4 (68... Qh6
69. f4 Qg7 70. Qxg7+ Kxg7 71. Bc6 $18) 69. Bxg6 Nxg6 70. Qxg6 Qxh4+ 71. Kg2 $1
$18) 1-0

[Event "Tilburg"]
[Site "?"]
[Date "1979.??.??"]
[Round "?"]
[White "Karpov, Anatoly"]
[Black "Hort, Vlastimil"]
[Result "1-0"]
[Annotator "JvR"]
[SetUp "1"]
[FEN "8/1pkr1p2/2p3pp/P7/2PP2PP/3K4/8/R7 w - - 0 58"]
[PlyCount "31"]
[EventDate "1979.??.??"]

{Lesson five. Blockade in general.   The aim of prophylaxis is to take away
possibilities from the opponent. Blockade, the simplest prophylaxis, will be
treated. If a piece is placed before a pawn, three advantages exist: the pawn
cannot advance, the pawn gives some protection to the blockader and the
blockader restricts the hostile mobility (Nimzowitsch). The example shows the
advantages of blockade in an elementary way.} 58. Rf1 $1 {Black has a backward
f-pawn. White has to take advantage immediately. Otherwise Black will
eliminate his only weakness.} 58... Kb8 $6 {The king will attack the a-pawn.} (
{More problems sets} 58... Kd6 59. Rf6+ Ke7 60. g5 hxg5 61. hxg5 Rc7 (61... Rd6
62. Rxd6 Kxd6 63. Ke4 {and White wins the pawn ending (Gligoric)}) 62. Kc3 Rc8
63. Kb4 Rh8 $1 (63... Ra8 {The attack on the queenside is stopped.} 64. d5 $1
cxd5 65. cxd5 Rd8 66. Kc5 $18) 64. a6 $1 bxa6 65. Rxc6 Rh5 66. Rxa6 Rxg5 67.
Ra7+ {White has an advantage in time. Probably, this will suffice for the win.}
) 59. Rf6 {The advantages of a blockade can be noticed: the f-pawn cannot be
moved, the blockader cannot be attacked and the blocader pressures on the
sixth rank.} 59... Ka7 60. h5 Ka6 61. g5 $1 {White has a nice decision.} 61...
hxg5 62. h6 Kxa5 63. h7 Rd8 64. Rxf7 b5 65. cxb5 Kxb5 (65... cxb5 {
creates a second passed pawn for White.}) 66. Rb7+ $1 {White gains a tempo.}
66... Ka6 67. Rg7 Rh8 68. Ke4 Kb5 69. Kf3 Kc4 70. Rd7 Kd3 71. Kg4 Rxh7 72. Rxh7
Kxd4 73. Rd7+ (73. Rd7+ {Again White wins a move.} 73... Kc4 74. Rc7 Kd5 75.
Kf3 $18) 1-0

[Event "Wch Moscow"]
[Site "?"]
[Date "1963.??.??"]
[Round "18"]
[White "Botvinnik, Mikhail"]
[Black "Petrosian, Tigran"]
[Result "0-1"]
[Annotator "JvR"]
[SetUp "1"]
[FEN "4r3/3rn1k1/1pp1bpn1/p5p1/P2PP1Pp/1P5P/3R1KN1/2RB1N2 w - - 0 41"]
[PlyCount "42"]
[EventDate "1963.??.??"]

{Lesson six. Blockade by the knight.   The knight can be far stronger than
other pieces as a blockader, because his influence is not affected in closed
positions. The knight always restricts the opponent. An example gives
clarification. Botvinnik thought that he had a favourable adjourned position
due to the occupation of the centre. A second with a different opinion was
sent away. However, Euwe already mentioned the vulnerability of the isolated
pawn centre in the 1920's.} 41. Bc2 $1 {Pawn e4 needs overprotection.} 41...
Bf7 $1 42. Nfe3 c5 $1 {Petrosian's prepared move.} 43. d5 Ne5 44. Rf1 $2 {
A wrong strategic choice decides the world championship match.} (44. Nc4 $1 {
responds to the blockade with the same idea.} 44... Nxc4 45. bxc4 Nc8 (45...
Bg6 46. Ne3 Nc8 47. Nf5+ $1 {(Kan)} 47... Bxf5 48. exf5 Rde7 {
"The position is hopeless" Timman evaluates.} 49. Bd3 Re3 50. Re2 $1 Rxe2+ 51.
Bxe2 Re4 52. Rb1 {White has a fortress.}) 46. Ne3 $1 ({
The analysts continue with} 46. e5 $6) 46... Nd6 47. Nf5+ Nxf5 48. exf5 {
White has a fortress again.} 48... Rde7 49. Rb1 Re3 50. Rb3 {White answers to
the invasion. Probably Petrosian had found this variation. Boleslavsky
convinced him to exhaust the old champ.}) 44... Bg6 45. Ke1 Nc8 46. Rdf2 Rf7
47. Kd2 Nd6 {The black knights blockade the centre. They restrict the white
pieces and support an attack on the queenside.} 48. Nf5+ Bxf5 49. exf5 c4 $1
50. Rb1 b5 51. b4 c3+ $1 {A beautiful decision.} 52. Kxc3 Rc7+ 53. Kd2 Nec4+
54. Kd1 Na3 55. Rb2 Ndc4 56. Ra2 axb4 57. axb5 Nxb5 58. Ra6 Nc3+ 59. Kc1 Nxd5
60. Ba4 Rec8 61. Ne1 Nf4 {Botvinnik got a lesson in strategy.} 0-1

[Event "Wch Moscow"]
[Site "?"]
[Date "1984.??.??"]
[Round "9"]
[White "Karpov, Anatoly"]
[Black "Kasparov, Gary"]
[Result "1-0"]
[Annotator "JvR"]
[SetUp "1"]
[FEN "8/8/p2k1p2/1p1p2pp/1P1P3P/P3NPP1/5K2/1b6 b - b3 0 46"]
[PlyCount "48"]
[EventDate "1984.??.??"]

{Lesson seven. Restriction in general.   The aim of restriction is to limit
the mobility of opponent as much as possible. The effect is retreat until no
ground is left. The specific case of blockade has been treated. Restriction in
general is the subject this time. White has a plus because the knight is
stronger than the bishop.} 46... gxh4 $6 (46... Bg6 {prepares the exchange.})
47. Ng2 $3 {Oleg Pervakov was among the spectators. He saw a wave of surprise
and enthusiasm among the public. A red headed Gary sat behind the board.} 47...
hxg3+ 48. Kxg3 {The white king is allowed to enter and restrict his collaegue.}
48... Ke6 $2 ({Correct is} 48... Bg6 49. Nf4 Bf7 $1 50. Kh4 Ke7 51. Nxh5 Ke6
52. Nf4+ Kf5 53. Nd3 Be8 $1 54. Kg3 Bd7 55. Nc5 Bc8 {
Black has a horrible position but he seems to survive.}) 49. Nf4+ Kf5 50. Nxh5
Ke6 51. Nf4+ Kd6 52. Kg4 Bc2 53. Kh5 Bd1 54. Kg6 $1 Ke7 {
The crucial position of the endgame.} (54... Bxf3 55. Kxf6 $18) 55. Nxd5+ $2 {
This move is an error although a pawn is won by a check. Pawn d5 should not be
captured immediately.} ({The restriction should continue with} 55. Nh5 $3 Bc2+
56. Kg7 Bd1 ({The pointe is} 56... Ke6 57. Ng3 $1 {and 58.f4.}) 57. Nxf6 Bxf3
58. Kg6 Ke6 59. Ne8 Kd7 60. Ng7 Ke7 61. Kf5 Kd6 62. Kf6 Bg2 63. Nf5+ Kd7 64.
Ke5 {
The preparation has been completed. White will gain pawn d5 and win eventually.
}) 55... Ke6 $6 (55... Kd6 56. Nxf6 Bxf3 {White wins easily according to
Geller and Mikhalchiskin. However pawn d4 is weak due to the missing pawn d5!})
56. Nc7+ Kd7 $2 {A second pawn will be lost.} ({Correct is} 56... Kd6 57. Nxa6
Bxf3 58. Kxf6 Kd5 59. Nc7+ Kxd4 60. Nxb5+ Kc4 61. Nd6+ Kb3 62. b5 Kxa3) 57.
Nxa6 Bxf3 58. Kxf6 Kd6 59. Kf5 Kd5 60. Kf4 $1 {The d-pawn is saved.} 60... Bh1
61. Ke3 Kc4 62. Nc5 Bc6 63. Nd3 Bg2 ({Or} 63... Be8 64. Ne5+ Kd5 {
(Averbakh and Taimanov).}) 64. Ne5+ Kc3 65. Ng6 Kc4 66. Ne7 Bb7 67. Nf5 {
The restriction of the black king has gone completely.} (67. d5 Bxd5 68. Nxd5
Kxd5) 67... Bg2 $4 {A blunder ends the game.} (67... Kd5 68. Kd3 Ke6 69. Ng3
Bg2 {and the game will be hard to win for White despite the two extra pawns.})
68. Nd6+ Kb3 69. Nxb5 Ka4 70. Nd6 {This endgame has been published without
criticism mostly. Restriction appears to be difficult for world champions too,
if proper analyses are made.} 1-0

[Event "Vancouver cqf"]
[Site "?"]
[Date "1971.??.??"]
[Round "4"]
[White "Fischer, Robert"]
[Black "Taimanov, Mark"]
[Result "1-0"]
[Annotator "JvR"]
[SetUp "1"]
[FEN "7r/1p1k1pp1/p4n1p/2p5/4RP2/6P1/PPP3BP/6K1 w - - 0 24"]
[PlyCount "95"]
[EventDate "1971.??.??"]

{Lesson eight. Restriction and time.  Restriction limits mobility. Sometimes
it leads to an undesired surplus in time: zugzwang. White has a slight
advantage in the example.} 24. Re5 $1 b6 $2 ({Radulescu suggests} 24... Kd6 $1
25. a4 $1 a5 $1 26. b3 b6 27. Bf1 Re8 $11) 25. Bf1 a5 26. Bc4 $1 Rf8 {
The mobility of the rook has been restricted. Taimanov tells in a booklet how
he only could admire, as 'Dr. Watson', the inteligence of 'Sherlock Holmes'
Fischer in the rest of the game.} 27. Kg2 Kd6 28. Kf3 Nd7 29. Re3 Nb8 30. Rd3+
Kc7 31. c3 Nc6 32. Re3 Kd6 33. a4 $1 {White has restricted the queenside.}
33... Ne7 34. h3 Nc6 35. h4 {The intention is the pawn avalanche h5, g4 and g5.
} 35... h5 {Black has to close the kingside. His pawns go to weak squares.} 36.
Rd3+ Kc7 37. Rd5 f5 {The closure of the flank has liberated the rook.} 38. Rd2
Rf6 39. Re2 Kd7 40. Re3 g6 41. Bb5 Rd6 42. Ke2 Kd8 $6 (42... Rf6 $1 {
avoids the exchange of rooks.} 43. Kd3 Rd6+ 44. Kc4 Rf6 45. Re1 $1 {
The aim is an exchange of moves.} 45... Rd6 46. Re2 Rf6 47. Re3 $1 {Zugzwang.}
47... Rd6 48. Rd3 {and exchange.}) 43. Rd3 Kc7 44. Rxd6 Kxd6 45. Kd3 {
The king penetrates.} 45... Ne7 46. Be8 Kd5 47. Bf7+ Kd6 48. Kc4 Kc6 49. Be8+
Kb7 50. Kb5 Nc8 $1 {
The restriction is not fatal right away due black's threat of mate in one.} 51.
Bc6+ Kc7 52. Bd5 Ne7 53. Bf7 $1 Kb7 54. Bb3 $1 Ka7 $1 {
Black stands with his back against the wall.} 55. Bd1 Kb7 56. Bf3+ Kc7 57. Ka6
{The restriction proceeds.} 57... Nc8 58. Bd5 Ne7 59. Bc4 Nc6 60. Bf7 Ne7 61.
Be8 $1 {Black has done a little as possible so far. Now he should like to pass,
but that is against the rules. He has a surplus in time due to zugzwang.} 61...
Kd8 {Black seems to have a last resource, but Fischer strikes.} 62. Bxg6 $1
Nxg6 63. Kxb6 Kd7 64. Kxc5 Ne7 65. b4 axb4 66. cxb4 Nc8 67. a5 Nd6 68. b5 Ne4+
69. Kb6 Kc8 (69... Nd6 70. a6 Nc8+ 71. Kc5 Kc7 72. Kd5 {
and the game is decided at the other flank.}) 70. Kc6 Kb8 71. b6 {
This great win was the fourth in a series of six.} 1-0

[Event "Groningen"]
[Site "?"]
[Date "1946.??.??"]
[Round "9"]
[White "Botvinnik, Mikhail"]
[Black "Euwe, Max"]
[Result "1/2-1/2"]
[Annotator "JvR"]
[SetUp "1"]
[FEN "2r5/7p/4k1p1/8/2p1PKPP/2R5/8/8 b - h3 0 39"]
[PlyCount "24"]
[EventDate "1946.??.??"]

{Lesson nine. Consolidation.  The protection of the own territory is called
consolidation. I distinguish passive consolidation, if the aim is only
defensive, and active consolidation, if an attack is prepared.  Black has a
distant passed pawn in a rook endgame. He threatens to defeat the opponent by
zugzwang. White has to try to preserve his territory. He threatens to play h5,
followed by exchange and a decrease of the pressure.} 39... h6 $6 ({
Better chances are offered by} 39... Rc5 $1 {(Flohr)} 40. e5 $1 {The new move}
40... h6 $1 {brings active consolidation. Black improves his position, while
White cannot do anything.} (40... Kd5 $6 41. Re3 $2 ({Correct is} 41. h5 $1 Rc6
42. hxg6 hxg6 43. Re3 Ke6 44. Rc3 Rc8 45. Kg5 Kxe5 46. Kxg6 $11) 41... c3 42.
e6 c2 $2 ({An improvement is} 42... g5+ $1 43. hxg5 (43. Kxg5 Kd4+) 43... c2
44. e7 c1=Q 45. e8=Q Rc4+ $1 46. Kf3 Qf1+ 47. Kg3 Qg1+ {
(the original intention of Bodaan)}) 43. e7 g5+ $1 44. Kxg5 Kd4+ 45. Kf4 Rc8 {
(Bodaan)} 46. Re1 Re8 47. Rc1 Kd3 48. Kg5 $11 {(Navara)}) ({
The old main line of Euwe is} 40... Rc8 41. h5 Kd5 42. hxg6 hxg6 43. Kg5 Rc6
44. Re3 Re6 45. Kf4 Kd4 46. Re1 c3 47. Rd1+ Kc4 48. Ke4 c2 49. Rc1 Kc3 50. Kd5
Re8 ({I added in 1993} 50... Rb6 $1 51. e6 Rb1 52. Rxc2+ Kxc2 53. Ke5 Rf1 54.
g5 Rf5+ 55. Kd6 Rf1 56. Ke5 $1 Kd3 57. e7 Kc4 58. e8=Q $1 Re1+ 59. Kf6 Rxe8 60.
Kxg6 Kd5 61. Kf7 $11) 51. e6 Kb2 52. Rh1 c1=Q 53. Rxc1 Kxc1 54. Ke5 Kd2 55. Kf6
Ke3 56. Kxg6 $1 Rxe6+ 57. Kf5 $1 $11) 41. Ke4 $1 (41. h5 $2 g5+ 42. Ke4 Rc7 $1
43. Kd4 Rf7 $1 $19) (41. g5 $2 h5 42. Ke4 Rxe5+ 43. Kd4 Kf5 44. Rf3+ Kg4 45.
Rf6 $1 Re7 46. Rxg6 Rc7 47. Rf6 c3 48. Rf1 c2 49. Rc1 Kxh4 50. g6 Kg5 $1 51. g7
Rxg7 52. Rxc2 Kf4 {Black wins theoretically.}) 41... Rc7 $1 (41... Rxe5+ 42.
Kd4 $11) 42. g5 hxg5 (42... h5 43. Kd4 Kf5 44. Rxc4 $11) 43. hxg5 Rh7 $1 ({
the manoeuvres} 43... Rc8 44. Kd4 Kf5 45. Rf3+ $1 Kxg5 46. e6 c3 47. Rxc3 Rxc3
48. Kxc3 Kf6 49. Kd4 Kxe6 50. Ke4 {draw}) 44. Rf3 $1 Rh4+ 45. Ke3 $1 Kxe5 46.
Rf6 Rh3+ 47. Kd2 {Black has won a pawn but not the game.}) 40. g5 h5 41. Ke3
Ke5 {White desires: 'They will not pass!', but he seems to lose by zugzwang.}
42. Rc2 $1 c3 43. Kd3 {An impressive passive consolidation has started.} 43...
Rd8+ ({The first point is} 43... Rc7 44. Rxc3 $1 Rxc3+ 45. Kxc3 {
White draws when he rushes with his king to f6.}) 44. Ke3 Rd4 45. Rxc3 Rxe4+
46. Kf3 Rxh4 47. Rc6 Rf4+ 48. Ke3 Re4+ 49. Kf3 Kf5 50. Rf6+ Kxg5 51. Rxg6+ $1 {
The second point secures the draw.} 1/2-1/2

[Event "Bled"]
[Site "?"]
[Date "1961.??.??"]
[Round "14"]
[White "Petrosian, Tigran"]
[Black "Bertok, Mario"]
[Result "1-0"]
[Annotator "JvR"]
[SetUp "1"]
[FEN "7b/3n1k1p/3p1ppP/2pPp3/n1P1P1P1/4BP2/4NK2/5B2 w - - 0 37"]
[PlyCount "51"]
[EventDate "1961.??.??"]

{Lesson ten. Fortification.  If a player applies fortification, a fortress is
built and attackers are observed.   The attacker has two narrow openings. "We
will smoke them out!" he claims. Notice Black's bishop of the sad figure.} 37.
Ng3 {This makes the advance of black's g- or f-pawn unfavourable. White starts
activity on the queenside after the consolidation of the kingside.} 37... Ndb6
{If Black wants to liberate the bishop, the knights have to move to e7 and f7
as preparation of ..g5 and ..Nxh6. This takes too long. So Black has to choose
for consolidation of the queenside.} 38. Bc1 Nc3 39. Ke1 Ke7 40. Kd2 Nca4 41.
Kc2 Nc8 42. Kb3 Nab6 43. Bh3 $1 ({More natural looks} 43. Bd3 {
but the bishop remains inactive in that case.}) 43... Kd7 44. Bd2 Ne7 {
Black stops the intruders easily, although his bishop has no positional value.}
45. g5+ $1 {This a-positional move is necessary for strategic reasons. White
opens a second front.} 45... Ke8 46. Ba5 Nec8 {
The knights are needed for the defence of the queenside.} 47. Nh1 $1 {
The plan is to play Be6 and Nf2-g4. It forces ..fxg5.} 47... fxg5 {
Black complies and activates his bishop..} 48. Nf2 Bf6 49. Bg4 Bd8 50. Nh3 Bf6
51. Bd2 Ne7 52. Nxg5 Bxg5 {The bishop has done its duty.} 53. Bxg5 {Black can d
o very little. One knight has to stop the penetration of white's king on the
queenside. If the other one jumps to c8, exchange follows. One guard suffices
at the moment.} 53... Kf7 ({Interesting is} 53... Kd8 $1 54. Be6 Ke8 55. Bh4 $1
{Zugzwang.} 55... Kd8 $6 (55... Kf8 56. Be1 Ke8 57. Ba5) 56. Bf7 Kd7 57. Bg5 $1
{Zugzwang again.} 57... Kd8 58. Bxg6 $1) 54. Bd2 $1 {
The bishop goes to a5, before the black king can reach c7.} 54... Nec8 55. Bxc8
Nxc8 {Cooperation between the strong bishop and active king will decide the
endgame quickly.} 56. Bg5 $1 {
Consolidation prevents a counteraction on the kingside.} 56... Nb6 57. Bd8 Nc8
58. Ka4 Ke8 59. Bg5 Kd7 60. Kb5 Kc7 61. Ka6 Nb6 {This allows an elegant move.}
62. Bd8+ $1 {The exchanges have led to a won pawn ending.} 1-0

[Event "Moscow"]
[Site "?"]
[Date "1967.??.??"]
[Round "?"]
[White "Keres, Paul"]
[Black "Portisch, Lajos"]
[Result "0-1"]
[Annotator "JvR"]
[SetUp "1"]
[FEN "8/8/3k2pb/1pn1p2p/pNp1P2P/P1P1NK2/1P4P1/8 b - - 0 45"]
[PlyCount "89"]
[EventDate "1967.??.??"]

{Lesson eleven. Strong and weak squares.  A square in or close to the own
position is strong if it can be controlled and possibly occupied (a definition
after Euwe and Reti). It is irrelevant if the square is occupied or empty. If
a square is controlled by a pawn, the opponent cannot control it (Euwe in
Tijdschrift 1929). Therefore we consider the pawn structure as essential when
we search for strong squares.  At the start of the next endgame, the squares
b3, b2, d3 and f4 are strong for Black. The square d5 is strong for White. The
squares b5, e5 and g6 are not strong for White, because it is hardly possible
to control them. So White has four strong square and White one.} 45... Nd3 $6 (
45... Nb3 $1 46. Ke2 Bf4 47. Na6 Bg3 {utilises the weak squares.}) 46. Nd1 Bc1
47. Ke2 $1 {Keres has set a wonderful trap.} 47... Nc5 (47... Nxb2 $2 48. Nxb2
Bxb2 49. Kd2 Bxa3 50. Kc2 Bxb4 51. cxb4 {
Black has won two pawns, but White has an impregnable fortress.}) 48. Kf3 g5
49. hxg5 Bxg5 50. Na2 Ke6 51. Nf2 Kf6 52. Nd1 Nd3 53. g3 Kg6 54. Kg2 Bd2 55.
Kf3 Kg5 56. Ke2 Be1 57. Kf3 Bd2 58. Ke2 Be1 59. Kf3 Kf6 60. Kg2 ({
Elegancy shows} 60. Nb4 Nxb4 61. cxb4 Bd2 $1 62. Ke2 Bc1 $1 63. Nc3 Bxb2 64.
Nxb5 Kg5 {(Barcza).}) 60... Kg6 $6 (60... Nc5 $1 61. Kf3 Ne6 62. g4 h4 $19) 61.
Kf3 Kg5 62. Kg2 h4 63. gxh4+ Kf4 $6 ({Black makes progress in} 63... Bxh4 64.
Kf3 Ne1+ 65. Ke3 Kg4) 64. h5 Kxe4 65. h6 Nf4+ 66. Kf1 Bh4 67. Nb4 Bf6 68. Ke1
Kf3 69. h7 Bg7 {Strong squares for Black are b3, b2, d3, h8 and h7. Strong for
White are b5 and g8. Black's great positional can be expressed in numbers this
way.} 70. Nc2 $2 (70. Nc6 $1 Nd3+ 71. Kd2 {The e-pawn will be stopped. It is
dangerous to conquer the h-pawn, because the active knight on c6 will attack
the weakness b5.}) 70... Nd5 $1 71. Kd2 Nf6 72. Ne1+ Ke4 73. Nf2+ Kf5 74. Ng2
Nxh7 {Black has won a pawn and finishes the game quietly.} 75. Ne3+ Ke6 76. Ne4
Bh6 77. Ke2 Bxe3 $1 78. Kxe3 Nf6 79. Ng5+ Kd5 80. Kf3 Nh5 81. Ne4 Nf4 82. Nf6+
Kc6 83. Ke4 Nd3 84. Ng4 Kd6 85. Nh6 Nxb2 $1 86. Nf7+ Kc5 87. Nxe5 Nd1 88. Nd7+
Kd6 89. Kd4 Nxc3 {The players produced a great positional game despite the
inaccuracies.  Counting strong and weak squares is a useful technique. If
strong squares are found near the own position, this gives information about
the restriction of the opponent. Appropriate consolidation leads to strong
squares in the own territory. Strong and weak pawns are found in the process.
This approach gives a useful source of information to human and computer.} 0-1

[Event "Amsterdam"]
[Site "?"]
[Date "1923.??.??"]
[Round "?"]
[White "Euwe, Max"]
[Black "Sonnenberg"]
[Result "1-0"]
[Annotator "JvR"]
[SetUp "1"]
[FEN "6k1/6pp/p1p1b3/1p1p4/1P6/2P4P/1P1N1PP1/6K1 w - - 0 35"]
[PlyCount "41"]

{Lesson twelve. Crossing a diagonal.  The bishop has a special effect on the
chess board. Connected squares on a diagonal become strong, while the adjacent
squares stay weak.  The limitations of a bishop become painfully clear in the
endgame of the weak bishop against the strong knight. Weak squares can be used
by the opponent as an entrance to the hostile position. A difficulty arises
when a strongly defended diagonal has to be crossed. An instructive endgame by
Euwe clarifies this process.} 35. Nf3 Bd7 {
Black has an awful pawn structure on the queenside.} 36. Ne5 Be8 37. f4 {
The strong knight has chased away the weak bishop.} 37... Kf8 38. Kf2 Ke7 39.
Ke3 Kd6 40. Kd4 {The white king has utilised weak squares for an advance.
Black can hardly move. If he allows an exchange of pieces, the pawn ending
will be lost. He tries to create a defence line on the kingside instead.} 40...
g6 41. Nd3 Bd7 42. Nc5 {White blockades on two squares.} 42... Bc8 {White seems
to have allowed a defence of the diagonal c8-h3, but Euwe crushes the
opposition. He crosses the Rubicon!} 43. g4 $1 h5 (43... h6 44. b3 $1 {
and Black has to play} 44... h5 {anyway.}) 44. f5 $1 gxf5 45. gxh5 f4 46. Nd3
Bxh3 ({The alternative} 46... f3 47. Ke3 Bf5 48. Nc5 a5 49. Nb7+ {
also offers little resistance.}) 47. Nxf4 Bf5 48. Nd3 Bh7 49. Nc5 {An immediate
advance is fine, but Euwe decides to gain a pawn. It increases the humiliation.
} 49... Bf5 50. Nxa6 Bh7 51. Nc5 Bf5 52. Nd3 Ke6 53. Ne5 Kd6 54. h6 {
The advance occurs.} 54... Be4 55. Nf7+ 1-0

[Event "Wijk aan Zee"]
[Site "?"]
[Date "1968.??.??"]
[Round "?"]
[White "Matanovic, Aleksandar"]
[Black "Korchnoi, Viktor"]
[Result "0-1"]
[Annotator "JvR"]
[SetUp "1"]
[FEN "4r1k1/1p4p1/p3p1n1/3p2Pp/7P/1NP1PNK1/PPb5/R7 b - - 0 29"]
[PlyCount "74"]
[EventDate "1968.??.??"]

{Lesson thirteen. The battle for an important square. Sometimes the struggle
in the endgame is decided by the fight for one square. Naturally this will be
a central square in most cases. E4 is the crucial point in the example.
Korchnoi has a favourable position due to the control over this square.} 29...
e5 {Black controls the centre.} 30. Nbd2 $2 {
White engages in the battle for e4.} (30. Nc5 $1 Ne7 $1 31. Nd7 $1 Nf5+ 32. Kf2
{brings counteraction.}) 30... Ne7 31. Re1 Nf5+ 32. Kh3 Nd6 $1 {
Black controls the square e4. This causes white passivity.} 33. Kg2 Kf7 34. Nf1
Ke6 35. Ng3 g6 36. Nd2 Rf8 37. Re2 b5 {
The struggle for the important square e4 reaches its highlight.} 38. Rf2 $2 {
White misses the last chance.} ({The time is ripe for} 38. e4 $1 {at last.}
38... Rf4 39. exd5+ Kxd5 40. Nf3 e4 41. Rd2+ Bd3 42. Ne1 {continues the battle.
}) 38... Bf5 39. Kf1 Rc8 40. Ke1 $6 {
The king is more active on e2. Slowly the white pieces move to poor squares.}
40... a5 {A minority attack starts.} 41. a3 b4 $1 42. axb4 ({Korchnoi mentions
} 42. cxb4 Rc1+ 43. Ke2 Bg4+ 44. Kd3 e4+ 45. Kd4 Nb5# {
The combination ends with a wonderful pointe.}) 42... axb4 43. Ne2 Ra8 44. Nb3
Ne4 45. Rh2 Rb8 46. cxb4 Rxb4 47. Nbc1 Nd6 $1 (47... Rxb2 $4 48. Nd4+) 48. b3
$6 (48. Nc3 {aims the knight on the square e4.}) 48... Ne4 49. Ng1 Nc5 50. Kd1
Nxb3 {The knight manoeuvre has netted a pawn.} 51. Rb2 Rg4 52. Nce2 Na5 53.
Rb6+ Ke7 54. Nf3 Nc4 55. Rb7+ Ke6 56. Ke1 Be4 57. Nd2 Nxd2 58. Rb6+ Kf7 59.
Rb7+ Kf8 60. Rb8+ Ke7 61. Rb7+ Ke8 62. Kxd2 Rxh4 63. Nc3 d4 64. Nxe4 Rxe4 65.
Rg7 Rxe3 66. Rxg6 0-1

[Event "Wijk aan Zee"]
[Site "?"]
[Date "1968.??.??"]
[Round "?"]
[White "Korchnoi, Viktor"]
[Black "Tal, Mikhail"]
[Result "1-0"]
[Annotator "JvR"]
[SetUp "1"]
[FEN "4r2k/3R3p/5p2/4p3/p6P/4PKP1/5P2/8 w - - 0 44"]
[PlyCount "31"]
[EventDate "1968.??.??"]

{Lesson fourteen. Overprotection. A chessman in the own position gets extra
support in the case of overprotection. The support to an advanced pawn in the
middle game is well-known. White gets support from behind in the following
endgame. The endgame is easily won, according to Keene. He is wrong as always.
  } 44. Ra7 Rb8 45. h5 Kg8 ({No use has} 45... Rb4 {due to} 46. h6 Kg8 47. Rg7+
Kh8 48. Rf7) 46. Rxa4 Rb7 (46... h6 47. Rg4+ Kf7 48. Rg6 {
and White wins a pawn.}) 47. Kg4 $6 {
The king stands slightly offside. Pawn f2 is the weakness in white's position.}
({The win is achieved more quickly in} 47. Ke4 $1 Rb2 48. f3 Rb3 49. h6 f5+ $1
50. Kxe5 Rxe3+ 51. Kf6 Re8 52. f4 $1) 47... Kg7 $6 {Tal fails to set problems.}
({Korchnoi analyses} 47... Rb2 $1 48. f3 Rb3 {He finds the complex win} 49. h6
$3 Rxe3 (49... f5+ 50. Kg5 $1) 50. Kf5 $1 Rb3 51. g4 Kf7 52. Ra7+ Kg8 53. Rg7+
Kh8 54. Rd7 Kg8 55. Ke6 $1 Rb6+ 56. Ke7 Rb8 57. Rd3 $1 Rf8 58. Ke6 Kh8 59. Kf5
Kg8 60. Rd6 {The win is clear at last.}) 48. Ra2 $1 {
Pawn f2 gets overprotection. Now, the win has become easily.} 48... Kh6 49. Kf5
Rb6 50. e4 Rc6 ({The tactical justification is} 50... Kxh5 51. f4 $1 Kh6 52.
Ra7 exf4 53. gxf4 Rb4 54. Rf7 {An encircling movement brings the victory.}) 51.
f4 exf4 52. gxf4 Rc5+ 53. Kxf6 Kxh5 54. e5 Kg4 55. f5 h5 56. Ra4+ Kg3 57. e6 h4
58. e7 Rc8 59. Kf7 1-0

[Event "Donetsk"]
[Site "Donetsk"]
[Date "2001.01.23"]
[Round "8"]
[White "Korchnoi, Viktor"]
[Black "Ponomariov, Ruslan"]
[Result "1-0"]
[Annotator "JvR"]
[SetUp "1"]
[FEN "r4rk1/p3npp1/1p2p2p/1P1pP3/5n2/P4N2/1P3PPP/1B1R1RK1 b - - 0 19"]
[PlyCount "94"]
[EventDate "2001.01.16"]
[Source "ChessBase"]
[SourceDate "2001.03.20"]

{Lesson fifteen. Counterattack: Direct confrontation. If the opponent looks
menacing, a player can do more than strengthen his own position. A
counterattack can be started in order to create the own chances. If attack and
counterattack take place on the same flank, a direct confrontation begins.
This way is symbolised by the punk head of Viktor Korchnoi. He applied the
approach in a match against Ponomariov.  } 19... g5 $1 {The position is equal.
Black starts an attack. He cuts potential support to e5 in order to conquer
the pawn later on.} 20. Rfe1 Rac8 21. h4 $5 ({
The own position can be strengthened by} 21. Nd4 Rc4 22. f3 {Then Korchnoi has
achieved little. He has to win in order to equalise the match. Therefore he
chooses the confrontation.}) 21... g4 22. Nh2 $5 {
The counterattack on the same flank continues.} 22... h5 23. f3 $5 g3 $1 24.
Nf1 Neg6 25. Rd4 $1 {White increases the counterattack. The exchange of the
black g- for the white h-pawn is unfavourable.} 25... Rc4 $2 {
Black is confused and blunders a pawn.} ({Ribli prefers} 25... Rc1 $5 26. Rxc1
Ne2+ 27. Kh1 Nxd4) ({I like the finish} 25... f5 $1 26. exf6 e5 27. Rd2 Nxh4
28. Ba2 Nh3+ 29. Kh1 Nf2+ 30. Kg1 Nh3+ {and perpetual check.}) 26. Rxc4 dxc4
27. Bxg6 $1 fxg6 (27... Nxg6 $5 28. Nxg3 Rc8 $1 29. Nxh5 Rc5 {is interesting.})
28. Nxg3 Nd3 29. Re2 Rd8 30. Ne4 $1 {
White returns the extra pawn in order to activate his knight.} 30... Nxe5 31.
Ng5 Rd5 32. a4 Kg7 33. Nxe6+ Kf6 34. Ng5 Kf5 35. Ne4 Rd3 36. Nc3 Rd4 37. Ne4
Rd3 38. Kh2 {White does not repeat the moves again.} 38... Rb3 $6 ({
The restriction of the white pieces is continued by} 38... Rd4 $1 39. Rc2 Ke6
40. Kh3 Nd3) 39. Nd6+ {
The counterattack has changed in an attack without restriction.} 39... Kf6 40.
Ne8+ Kf5 41. Nd6+ Kf6 42. Kg3 Rb4 43. Re4 $1 Ke6 $1 ({Avoids} 43... Rxb2 $2 44.
Rxe5 $1) ({and} 43... Rxa4 44. b3) 44. Nc8 Kf6 $1 45. Nxa7 Rxa4 ({
Korchnoi analyses the counterattack} 45... Rxb2 $2 46. Nc6 $1 Nd3 47. Rxc4 Ne1
48. Re4 Rxg2+ 49. Kh3 Rg1 50. a5) 46. Nc6 Nd3 47. Ne7 Nxb2 48. Nd5+ Kf7 $2 {
Hereafter Black is lost.} (48... Kf5 49. Nxb6 Rb4 {
keeps Black in the game (Korchnoi).}) 49. Re7+ Kf8 50. Rb7 Nd1 51. Rxb6 c3 52.
Rc6 Ra5 53. b6 Rb5 54. Rc7 Rxd5 55. b7 Rb5 56. Rc8+ Kf7 57. b8=Q Rxb8 58. Rxb8
c2 59. Rc8 Ne3 60. Kf2 Nf5 61. g3 Nd4 62. g4 Ke6 63. Ke3 Kd5 64. Rc3 g5 65.
hxg5 hxg4 66. fxg4 1-0

[Event "Berlin"]
[Site "?"]
[Date "1910.??.??"]
[Round "7"]
[White "Schlechter, Carl"]
[Black "Lasker, Emanuel"]
[Result "1/2-1/2"]
[Annotator "JvR"]
[SetUp "1"]
[FEN "r3k2r/p3p2p/b1ppP1p1/5p2/N2b1Bn1/1B6/PPP2PPP/R4RK1 w kq - 0 15"]
[PlyCount "68"]
[EventDate "1910.??.??"]

{Lesson sixteen. Counterattack: the flight forwards Sometimes a player
experiences great problems by an attack of the opponent on a certain area of
the board. Only a counteraction in another area might give solace. Schlechter
adopts a flight forwards hereafter.   } 15. c4 O-O ({The line} 15... Be5 16.
Bxe5 Nxe5 {(Bernstein)} 17. Rac1 {leads to a defendable position for White.})
16. Rad1 Bf6 17. Rfe1 g5 $1 {Lasker grabs the initiative. Schlechter changes
the intended attack in a flight forwards.} 18. Bxd6 $5 ({He wants to avoid} 18.
Bd2 Ne5 {but} 19. c5 $1 {would have be a fine answer. Carl meets an unfair
tratment in Berlin and plays too sharp. He wants to silence his critics.})
18... exd6 19. Rxd6 Be5 20. c5 $1 (20. Rxc6 $2 Bb7 21. Rc5 Bd4 $1 {
ends in a disaster.}) 20... Rfe8 $6 {Suddenly the great fighter becomes shy.} (
{The crucial line is} 20... Bxh2+ 21. Kh1 Bxd6 22. cxd6 Nxf2+ 23. Kg1 Ne4 24.
e7+ Kg7 25. exf8=Q+ Rxf8 {A variation of Tarrasch continues by} 26. d7 Rd8 27.
Rxe4 $1 fxe4 28. Nc5 Kf6 29. Nxa6 Rxd7 {Huebner regards} 30. Nc5 Rd4 {
as better for Black.}) 21. g3 Bf6 22. Rxc6 Bb7 $6 (22... Bb5 {
keeps a plus (Capablanca).}) 23. Rc7 Be4 24. Nc3 Bxc3 25. bxc3 Ne5 26. Rd1 Nf3+
(26... Kh8 $6 {(Bernstein)} 27. f4 gxf4 28. gxf4 Nd3 29. Kf1 {
(threatens Bc4). White has a sharp attack.}) 27. Kf1 Nxh2+ 28. Ke1 Nf3+ 29. Ke2
Ne5 30. Rdd7 $1 {
White has conquered the initiative by a fine charge in the centre.} 30... f4 $1
(30... Nxd7 $2 31. exd7+ Bd5+ 32. dxe8=Q+ Rxe8+ 33. Kf1 {
loses material for Black.}) 31. Rg7+ Kh8 32. Rxg5 Bd3+ 33. Kd1 fxg3 $1 34. fxg3
({Not} 34. f4 $2 Rg8 $1 {(Bernstein).}) 34... Ng6 35. Rd5 Be4 36. Rd6 Bf5 $6 (
36... a5 37. Rd2 a4 38. Bc4 Rac8 {brings a better defence.}) 37. Bd5 $6 {
White will lose his advantage.} ({Better is} 37. Kd2 $1 a5 (37... Nf8 $6 38.
Rf7 $1 Bxe6 39. Rxf8+ $1 Rxf8 40. Bxe6) 38. Rf7 Bh3 39. Bd5 Rac8 40. c6 {
continues the attack.}) 37... Rab8 38. c6 Nf8 39. Rb7 Rbc8 40. e7 Ng6 41. Bf7
Rxe7 42. Bxg6 Bg4+ $1 43. Kc1 Re1+ 44. Kb2 hxg6 45. Rxg6 Bf5 46. Rf6 Be4 47.
Rxa7 Rb1+ 48. Ka3 Bxc6 {
A great fight with chances for both sides ends peacefully.} 1/2-1/2

[Event "Hastings"]
[Site "?"]
[Date "1895.??.??"]
[Round "21"]
[White "Pillsbury, Harry"]
[Black "Gunsberg, Isidor"]
[Result "1-0"]
[Annotator "JvR"]
[SetUp "1"]
[FEN "1n6/4k2p/p3ppp1/1pPp4/3P1PP1/3NP3/P3K2P/8 w - - 0 27"]
[PlyCount "27"]
[EventDate "1895.??.??"]
[Source "ChessBase"]

{A chess position can be described in terms of matter, space and time (wood
stands on the board at a move). If you want to achieve something, you have to
devise a pocket strategy. If you give matter in order to win time, a
development sacrifice is made in the opening. It often happens to be a
breakthrough in the endgame.   Lesson seventeen. The breakthrough by pawns. A
breakthrough is essential in warfare. After trenches had been dug in World War
I, an advance became impossible. An opening emerged, when tanks were used in
Cambrai. Tanks and infantry moved forward. However, the hole was too small for
the cavalry to reach the green fields beyond. A similar case developed in
piece time. Pillsbury had to win in the last round of a legendary British
tournament. Little happened in the game. Suddenly he got an opportunity. The
black pawn structure seems secure, but Harry scores by a breakthrough. A
famous combination begins.} 27. f5 $1 g5 ({Lasker analyses} 27... gxf5 28. gxf5
exf5 29. Nf4) ({and} 27... exf5 28. gxf5 g5 29. Nb4 {Pawn d5 falls each time.})
28. Nb4 a5 {Black has to attack the knight.} 29. c6 $1 Kd6 30. fxe6 $1 Nxc6 ({
Or} 30... axb4 31. e7 $1 Kxe7 32. c7) 31. Nxc6 Kxc6 32. e4 $1 dxe4 33. d5+ Kd6
34. Ke3 b4 35. Kxe4 a4 36. Kd4 {White has punched a hole in the centre. 'The
green fields beyond' come in sight. Still the troops are stopped despite the
local superiority. Black threatens to break through on the flanks and reach
his own 'green fields'.} 36... h5 ({The main line continues with} 36... Ke7 $1
37. Kc4 b3 38. axb3 a3 $1 39. Kc3 f5 40. gxf5 h5 41. b4 $1 g4 42. b5 h4 43. b6
a2 44. Kb2 g3 45. hxg3 hxg3 46. d6+ Kxd6 47. b7 Kc7 48. b8=Q+ Kxb8 49. e7 a1=Q+
50. Kxa1 g2 51. e8=Q+ {
(Lasker). A check decides after a combination of twenty-five moves.}) 37. gxh5
a3 38. Kc4 f5 39. h6 f4 40. h7 {Pillsbury had won Hastings 1895 by a victory
in the last round! The combination became an evergreen.} 1-0

[Event "Baguio City"]
[Site "?"]
[Date "1978.??.??"]
[Round "28"]
[White "Karpov, Anatoly"]
[Black "Kortschnoj, Viktor"]
[Result "0-1"]
[Annotator "JvR"]
[SetUp "1"]
[FEN "r3k3/5p2/2p3p1/1p1pP1nr/pP6/2P5/P4PP1/R3RNK1 b q - 0 28"]
[PlyCount "67"]
[EventDate "1978.??.??"]
[Source "ChessBase"]

{Lesson eighteen. The breakthrough by pieces. The previous time pawns advanced.
This time the elephants make an opening. Kortschnoj has a deficiency of 2-5 in
won games. This is almost fatal. It stimulates a fighter like Kortschnoj
enormously. He would like to stampede his elephants from a5 and h5 into the
hostile position, but the openings are too small.  } 28... Rh4 29. Rad1 Ke7 30.
f3 Ne6 31. Ne3 Rd8 $1 {An obvious plan is to double the rooks on the h-file,
but that does not create a threat.} 32. Ng4 Ng5 33. Ne3 Ne6 34. Ng4 Ng7 35. Ne3
Nf5 $1 36. Nc2 {If White exchanges the knights, the restraint will increase.}
36... Rc4 {Black utilises a hole.} 37. Rd3 d4 $1 {
Black applies a pawn breakthrough under time pressure.} 38. g4 Ng7 $1 39. Nxd4
Ne6 40. Red1 Nxd4 41. cxd4 Rxb4 {
Black has regained the pawn. The opening on the queenside becomes bigger.} 42.
Kf2 c5 $1 {Kortschnoj has set a new problem with his sealed move.} 43. d5 $1 ({
Analysts regard} 43. Ke3 {as drawn, but} 43... Rdxd4 $1 44. Rxd4 cxd4+ 45. Rxd4
Rb2 {wins for Black.}) 43... Rb2+ 44. Kg3 $2 {
Karpov and his seconds have analysed the adjourned position incorrectly.} ({
A draw can be forced by} 44. R3d2 Rxd5 $1 45. Rxb2 Rxd1 46. Rxb5 Rd2+ 47. Ke3
Rxa2 48. Rxc5) 44... Rxa2 {The intruder has cleared the pawns on the queenside.
} 45. Re3 b4 46. e6 Ra3 $1 {The aim is to pin the f-pawn.} 47. Re2 ({
Langeweg analyses the alternative} 47. Rxa3 bxa3 48. exf7 Rb8 $1 49. Ra1 Rb3
50. Kf4 Kxf7 51. Ke5 Ke7 $1 52. d6+ Kd7 {and Black wins.}) 47... fxe6 48. Rxe6+
Kf7 49. Rde1 ({Timman mentions the prophylactic} 49. g5 Rd7 $1) 49... Rd7 ({Not
} 49... Rxd5 50. Re7+ {drawn.}) 50. Rb6 Rd3 51. Ree6 R3xd5 52. Rxg6 a3 53.
Rbf6+ Ke7 54. Re6+ Kf8 55. Ref6+ Ke7 56. Re6+ Kd8 57. Ra6 Rb7 58. Rg8+ Kc7 59.
Rg7+ Rd7 60. Rg5 b3 61. Rxc5+ Kb8 {Black has avoided perpetual chech. When
this game occurred, I visited Chicago for medical research. An American of a
chess club and I were highly impressed by Kortschnoj's play.} 0-1

[Event "London - Edinburgh"]
[Site "corr 1824-28"]
[Date "1826.??.??"]
[Round "5"]
[White "Edinburgh Chess Club"]
[Black "London Chess Club"]
[Result "1-0"]
[Annotator "JvR"]
[SetUp "1"]
[FEN "2R5/p5pk/1pp4p/5P2/6P1/R1b2P1K/P5PB/2r4r w - - 0 37"]
[PlyCount "47"]
[EventDate "1824.??.26"]

{Lesson nineteen. The positional manoeuvre. If a player sacrifices time in
order to improve the own position or weaken the opponent, I call it a
prophylactic or positional manoeuvre. This manoeuvre occurred in an old match
of Edinburgh and London which started in 1824. The moves were sent weekly per
postal coach. A cup of 25 Guineas was the prize. The Scotch Gambit Cup still
exists. Three years after the start, the decisive phase in the fifth and last
game had been reached. Both cities play for mate. Black has progressed best.
Therefore, White has to give two moves in order to strengthen the own position.
  } 37. f4 $1 Bd2 38. g3 $1 {White has answered the threats.} 38... Ba5 $1 ({
Not} 38... Rc2 $2 39. g5 $1 {(Lewis).}) 39. Re3 $1 {
White sacrifices his bishop.} 39... Rc2 40. g5 $1 Rhxh2+ 41. Kg4 h5+ 42. Kf3
Rhf2+ 43. Ke4 {Suddenly White can develop a winning attack.} 43... g6 44. Rc7+
Kg8 45. Ke5 $1 Rc5+ $1 (45... Bc3+ 46. Rxc3 $1 Rxc3 47. Kf6 $1 {mates (Lewis).}
) 46. Kf6 Rxf5+ 47. Kxg6 Rf8 48. Rg7+ Kh8 49. Kh6 Bb4 $1 50. Re6 $1 {
White threatens to mate in two.} 50... Rf5 51. Rh7+ Kg8 52. Rg6+ Kf8 53. Rxc6
Rc5 54. Rf6+ Ke8 55. g6 $1 Rc3 56. g4 $1 Bf8+ {A fascinating finale follows.}
57. Rxf8+ $1 Kxf8 58. g7+ Kf7 59. Rh8 Rc6+ 60. Kh7 {A fine game concluded the
match. The white king was chased over the board and emerged as winner. The
Edinburghers had won with 2-1 and got the cup. Analyses by Lewis remained
worthwhile. Some later matches have been selected for this review, but the
level of the first one remained unsurpassed in the nineteenth century.} 1-0

[Event "World Champions Jubilee"]
[Site "ICCF Email 2001-04"]
[Date "2001.??.??"]
[Round "?"]
[White "Umansky, Mikhail"]
[Black "Berliner, Hans"]
[Result "1-0"]
[Annotator "JvR"]
[SetUp "1"]
[FEN "r7/p1p3k1/3pPN1p/2pPn1p1/8/6P1/P6P/5RK1 w - - 0 31"]
[PlyCount "37"]
[EventDate "2001.??.??"]

{Lesson twenty. Zugzwang. The aim of a positional manoeuvre is to lose time in
order to strengthen the own position or to weaken the opponent. This time such
a manoeuvre leads to zugzwang. The tormented chess player would like to skip a
move but that violates the rules. The next fragment stems from a chess
tournament among nine world champions of correspondence chess.  } 31. h4 $1 {
Umansky can win the exchange but he betters his position firstly.} 31... Rc8
32. h5 $1 c4 $1 33. Kg2 a5 34. a4 $1 {
Black has to weaken his position due to mutual zugzwang.} ({Premature is} 34.
e7 $2 Kf7 35. e8=Q+ Rxe8 36. Nxe8+ Kxe8 37. Kf2 {due to} 37... Ng4+ $1) 34...
g4 $5 {He takes square g4 from his knight.} ({The complex variation} 34... Ra8
$5 35. Nd7 $1 Nxd7 36. Rf7+ Kg8 37. Rxd7 Rc8 38. Kf3 $1 c3 39. Ke3 c2 40. Kd2
c6 $1 41. Kxc2 cxd5+ 42. Kd3 Kf8 43. Kd4 Rc4+ 44. Kxd5 Rxa4 45. Rf7+ Ke8 46.
Kxd6 Ra3 47. g4 Rd3+ 48. Ke5 Re3+ 49. Kf6 Rf3+ 50. Kg7 {
leads to a White win (after Umansky).}) 35. e7 $1 Kf7 36. e8=Q+ Rxe8 37. Nxe8+
Kxe8 38. Kf2 Ke7 39. Ke3 c6 40. Ke4 Nf3 ({Or} 40... c5 41. Kf5 $1 Nd3 42. Kg6
c3 43. Kxh6 {and the h-pawn decides the game (Umansky).}) 41. Rc1 c5 42. Kf5
Ne5 43. Rc2 $1 Kf7 44. Rb2 Nd3 45. Rb7+ Kf8 46. Kf6 $1 Ke8 47. Ke6 Kf8 48. Rf7+
Kg8 49. Rf1 {The win caused a sensation. Umansky became the champion of
champions by an impressive score of 7/8. Palciauskas, Timmerman and Baumbach
shared rthe second place.} (49. Rf1 c3 50. Kxd6 $1 c2 51. Kc7 c1=Q 52. Rxc1
Nxc1 53. d6 {and the d-pawn rules.}) 1-0

[Event "Wijk aan Zee"]
[Site "?"]
[Date "2003.??.??"]
[Round "5"]
[White "Kramnik, Vladimir"]
[Black "Bareev, Evgeny"]
[Result "1-0"]
[Annotator "JvR"]
[SetUp "1"]
[FEN "r1n4r/p1k2pp1/2p1p2p/1pP1P2P/6P1/1P2B3/P1K2P2/3R3R w - - 0 27"]
[PlyCount "43"]
[EventDate "2003.??.??"]
[Source "ChessBase"]
[SourceDate "2003.04.01"]

{Lesson twenty-one. Positional sacrifice: win. Material is sacrificed in order
to strengthen the own position or weaken the opponent. This sacrifice rarely
occurs in practice. A bishop is given in order to achieve the win in this
example. White controls the d-file and exerts pressure of the f-file.  } 27.
Rh3 $1 Ne7 28. Rf3 Rhf8 29. Rd6 $1 a5 30. g5 $1 {
The attack on the kingside begins.} 30... hxg5 ({The immediate} 30... Nf5 $6 {
allows the positional sacrifice} 31. gxh6 gxh6 32. Rxf5 $1 exf5 33. Rxh6 $1 Rh8
34. Rf6 {(Kramnik).}) 31. Bxg5 Nf5 $1 {The knight has to control h6. Pawn f7
needs indirect protection. Black has lost the struggle for the d-file, because
the knight cannot go to d5 and square d8 cannot be occupied by a rook.} 32. Rd1
a4 33. b4 {Black has to look for counter-play, if he wants to survive.} 33...
Kc8 $2 {Black becomes completely passive.} ({The counterattack} 33... Rh8 $1
34. Rfd3 Raf8 $1 {develops the rooks and attacks a pawn.} 35. Rd7+ Kb8 $1 {
White has not a decisive attack (Lukacs).}) 34. Rfd3 Ra7 35. Rd8+ Rxd8 36.
Rxd8+ Kb7 37. Kc3 Ka6 38. Kd3 $1 Rc7 39. Ke4 Kb7 40. Rd1 Kc8 41. Rd8+ Kb7 42.
Kf4 $1 Rc8 43. Rd7+ Rc7 44. Rd3 Kc8 ({Black repeats the moves because} 44...
Rc8 {fails due to} 45. Bd8) 45. Rd8+ Kb7 {An unexpected decision occurs.} 46.
Bf6 $3 {White brings a magnificent positional sacrifice. He threatens with the
continuation 47.Bxg7.} 46... g6 (46... gxf6 47. exf6 Rc8 48. Rxc8 Kxc8 49. Kg5
$1 Kd7 50. h6 Nxh6 51. Kxh6 e5 52. Kh7 $1 {
and White wins the tempo play (Kramnik):} 52... e4 53. Kg7 Ke6 54. a3) 47. hxg6
fxg6 48. Kg5 {Kramnik plays a perfect combination of combinatory struggle and
subtle prophylaxis.} 1-0

[Event "San Sebastian"]
[Site "?"]
[Date "1912.??.??"]
[Round "4"]
[White "Schlechter, Carl"]
[Black "Nimzowitsch, Aaron"]
[Result "1/2-1/2"]
[Annotator "JvR"]
[SetUp "1"]
[FEN "r1r3k1/1p3ppp/p3pn2/1bB5/8/3B4/PPP2PPP/3R1RK1 w - - 0 20"]
[PlyCount "119"]
[EventDate "1912.??.??"]
[Source "ChessBase"]

{Lesson tenty-two. Positional sacrifice: draw. Material is sacrificed in order
to strengthen the own position or weaken the opponent. A pawn sacrifice often
occurs in a rook ending in order to improve the own position. A pawn sacrifive
even happens twice in the example. White is weak on the c-file.} 20. Bd4 Bxd3
21. Rxd3 $5 {He makes a choice between two evils.} ({The alternative} 21. cxd3
Nd5 {leads to positional misery.}) 21... Rxc2 22. Rb3 b5 23. Bxf6 gxf6 {
The ending of four rooks gives fine drawing chances.} 24. Rd1 Rac8 25. Kf1 f5
$5 (25... R8c5 $1 {wins, according to Tarrasch, but White plays} 26. Rd8+ Kg7
27. Ra8 {and the game continues.}) 26. Ke1 R8c4 27. Rd2 $1 Rc1+ 28. Ke2 Ra4 29.
a3 Rg1 30. Rg3+ Kf8 31. b4 $5 Ra1 32. Rdd3 Ra2+ 33. Ke1 f4 34. Rh3 Kg7 35. Rb3
Kg6 36. Rhc3 f5 37. g3 fxg3 38. hxg3 e5 39. Kf1 Kg5 40. Kg2 h5 41. Rd3 e4 42.
Re3 Rc2 ({More consistent is} 42... h4 43. gxh4+ Kxh4 {
but the winning chances are minimal.}) 43. Kf1 a5 44. bxa5 Rxa5 45. Rb4 Ra2 46.
Reb3 Rc2 {White could have captured on b5, but he follows the motto: "I do not
do anything, because I do not have to think in that case".} 47. Kg1 Ra2 48. Kf1
Rc2 49. Kg1 Rd2 50. Kf1 Ra2 51. Kg1 h4 52. gxh4+ Kxh4 53. Rxb5 Rxb5 54. Rxb5
Kg4 55. Re5 $1 {Schlechter gives another pawn.} ({He avoids the trap} 55. Ra5
f4 $1 {and Black wins.}) 55... Kf4 56. Ra5 Kg4 57. Re5 Rxa3 58. Kg2 Ra8 59. Kf1
Ra1+ 60. Kg2 Rb1 61. Re8 Kf4 62. Ra8 Rc1 63. Rb8 Ra1 64. Rc8 Rd1 65. Ra8 Rd2
66. Re8 Ra2 67. Re7 Re2 68. Ra7 Rd2 69. Re7 Rd8 70. Ra7 Ke5 71. Kf1 f4 72. Re7+
Kd4 73. Ke2 Ra8 74. Rd7+ Ke5 75. Re7+ Kd5 76. f3 $5 {
Nimzowitsch does not accept a draw. So Schlechter contemplates for a minute.}
76... e3 ({The pointe is} 76... Ra2+ 77. Ke1 exf3 78. Kf1) 77. Re4 Rf8 78. Ke1
Rf5 79. Ke2 {Black cannot make any progress. It is a positional draw.} 1/2-1/2

