by Richard Bozulich
© Copyright 2015 by Richard Bozulich
All rights reserved according to international law. No part of this work may be reproduced by any mechanical, photographic, or electronic process, nor may it be stored in a retrieval system, transmitted, or otherwise copied for public or private use without written permission from Kiseido Publishing Company.
This position is from a game between Sakata Eio (White) and Rin Kaiho. Black invades White's corner enclosure by attaching at 1. With this move, Black is forcing White to decide whether he is going to take the territory in the corner or the territory on the top left.
If White answers Black 1 with the connection of 2, he indicates his intention to make territory on the top left. Having determined this, Black immediately plays a reducing move with 3, forcing White to defend with 4. He then invades with 5, attacking the marked stone and threatening to slide into White's territory with 'a'.
Black still has aji in the corner. Namely, he can start a ko there with the moves to 7. This is an annoying ko for White because Black can resolve it by capturing at 'a', threatening to wipe out White's territory on the top left. If White connects at 'a', Black resolves the ko by connecting between 5 and 3 and living outright.
After Black 5 in Dia. 2 White could eliminate this bad aji by making another move in the corner, but at this stage of the game, there are bigger and more urgent issues to attend to. Situations like this where finding the right time for Black to start this ko or for White to prevent it is what makes go such a difficult game strategically.
Black must not reverse the order of 1 and 3 in Dia. 2. White 2 reinforces his territory on the top left, so it will now be more difficult for Black to invade there. After Black attaches with 3, White secures the corner with 4 to 8 and Black's stones at 5 and 7 will have a very difficult time settling themselves.
If Black omits the probe of Black 1 in Dia. 1 and immediately invades with 1 in this diagram, White will jump down to 2, then answer Black 3 by expanding his territory on the top left with 4. Now the attachment of Black 5 is no longer a probe, as White has committed himself to making territory on the top left. White answers Black 5 by going for the corner with 6 and White's position in the top left is too strong and Black will have a hard fight to establish a position there.
In the game in Dia. 1, White answered Black 1 by going for the corner with 2. Black switched to the top left by clamping with 3 and peeping with 5. After White 6, Black extended to 7 and the position at the top was even: Black and White each secured a corner and each ended up with an unsettled group at the top.
Pawns and pawn chains
1. A good pawn-chain shape from the player's perspective is the shape of a triangle ▲, with the apex pointing upward.
2. Pawn chains are strong. Avoid splitting them into more than two separate chains.
3. Isolated pawns can be a liability in the middle game. Avoid them until the end game.
4. The isolated queen pawn can be an advantage in the middle game. Since the queen bishop's pawn and the king's pawn are missing, your pieces will have more room to maneuver, but it can be a disadvantage in the endgame.
5. Exchange an isolated queen pawn before the endgame.
6. Avoid creating doubled pawns.
7. Avoid creating hanging pawns.
8. Avoid creating a backward pawn
9. Don't advance a backward pawn.
10. A strong center pawn position makes a good base from which to launch an attack.
12. Unless you are planning a king-side attack, avoid prematurely advancing the pawns in front of your castled king until the endgame.
13. A passed pawn can give you an advantage by requiring your opponent to use a piece to block its advance.
14. In the endgame, passed pawns on the rook's file are weaker than passed pawns on other files, as it is easier for the opponent's king to block it.
15. When you have a pawn majority on one side, the unopposed pawn is the candidate to become the passed pawn. The other pawns are to be regarded as supports. (Nimzovich)
16. Block a passed pawn by placing a piece directly in front of it. (Nimzovich)
17. When trying to queen a passed pawn, put your rook behind it.
18. Avoid putting your rook in front of a passed pawn.
19. If you are trying to stop a passed pawn from queening, put your rook behind the pawn, attacking it from the rear.
20. Do not put your rook in front of a passed pawn unless you have no choice.
21. Passed pawns should advance.
22. Opposed pawns, where there is an enemy pawn on the same file, should often be held back.
23. In the endgame, the advancing pawn must must stay in close contact with its allies.
24. Never play to win a pawn if your development is unfinished.
Knights and Bishops
25. Develop knights before bishops. Knights have a short range so they should be brought out first.
26. Develop your bishops early, as your pawn chains may block its development and hence its movement.
27. Knights are more useful than bishops in closed positions.
28. Bishops are more useful than knights when there are many open diagonals.
29. In an open position, two bishops are a big advantage.
30. Knights are more efficient when placed in the center of the board and least efficient on the rook files. 'A knight on the rim is grim.'
31. A supported knight on the d6 or e6 square which can't be driven away by your opponent's pawns can give you a positional advantage.
32. In the endgame, knights are weaker than bishops in stopping the opponent's pawns from advancing.
33. In the end game, when your opponent threatens to advance pawns on both the left and the right flanks, a knight will be helpless.
34. In the end game, a bishop is better than a knight when your opponent has pawns on both the left and right flanks.
35. Bishops are more useful than knights in the end game.
36. In the endgame, two bishops will generally defeat a bishop and a knight.
37. If the bishop controls the long diagonal towards your opponent's castled king, an attack on the king side is possible.
38. In the endgame, a bishop and some linked pawns can support a pawn advance or it can delay your opponent's pawn advance.
39. In the endgame, a pair of bishops is more advantageous than a pair of knight's.
40. Rooks work most efficiently on open files.
41. Two rooks on same open file provide opportunities to attack.
42. Two rooks on the 7th or 8th rank have great potential to mate or to gain material.
43. In the endgame, two rooks in an open position are often stronger than a queen, especially if most of the minor pieces and pawns have been traded off.
44. In endings where you have King, Rook and Pawn against a King and Rook, place your rook behind the pawn and your king next to the pawn.
45. A queen is most effective in combination with a rook or a minor piece.
46. Avoid developing the queen during the opening, as it will probably be harassed by the opponent's minor pieces and cause a loss of tempo.
47. Usually it is best to castle early, particularly when castling on the king side. Castle for a specific reason. Usually to protect the king from immediate attack while developing the rook. But absent any threat it is often advantageous to continue development and leave your options open (aji) as to which side to castle or forgo castling altogether.
48. When the kings are castled on opposite sides, you can attack by advancing your pawns toward the opponent's king.
49. When the kings are castled on the same side, do not start an attack on the king too early; maneuver on the other side instead.
50. Kings should advance into the center after the major pieces are removed from the board.
51. Keep the king near your pawn chains to support their advance.
52. In king and pawn endings, the king should stay ahead of the pawns.
53. In the endgame, provide a shelter for the king in case it is attacked.
Exchanges should be made with a particular objective in mind.
54. Exchange to gain a tempo or to prevent the opponent from gaining a tempo.
55. Exchange to seize or open a file.
56. Exchange to eliminate a defending piece.
57. Exchange to avoid losing a tempo by retreating.
58. Exchange to eliminate weak pawns.
59. Exchange if you have a material advantage.
60. Exchange an inactive piece for one of your opponent's active pieces.
61. Develop your pieces quickly. Every piece should be developed using only one move.
62. In the opening, avoid moving the same piece twice.
63. Every pawn move must be regarded as a loss of tempo unless it helps to build or support the center or attacks the enemy's center.
"In the opening, one or two pawn moves, no more." (Lasker)
64. In general, pawn moves on the flanks result in a loss of tempo.
65. Try to control as many of the center d4, d5, e4, and e5 squares as you can.
66. Control the center with pieces instead of pawns. (Nimzovich)
The hyper-modern strategy for doing this is to develop the bishop on the second rank of the adjacent knight file the fianchettoed bishop. These are the ideal squares to place the bishops, as each one is placed on their longest diagonals, controlling the maximum number of squares.
67. Delay direct occupation of the center with pawns and undermine the opponent's pawns, using a fianchettoed bishop.
68. Avoid exchanging fianchettoed bishops, as the squares they were protecting will become weak.
69. Overprotect pieces and pawns under attack. (Nimzovich)
70. Don't attack until you have developed all of your pieces.
71. When the center is locked, start an attack on the flanks.
72. If two pieces are attacking your position, drive off one of those pieces by advancing a pawn.
73. Play moves with more than one meaning. For example, a pawn move may attack a piece while opening a diagonal for your bishop.
1. The pin
2. The skewer
3. Discovered check
4. Double check
5. The see-saw
6. Double attacks (forks executed by pawns and other pieces)
7. Removing the guard
8. Protection by interposing a piece.
9. Zwischenzug (an intermediate move)
10. Smothered mate
11. Perpetual check
12. Zugzwang (compulsion to move. Unlike in go, passing is not allowed in chess)