Chess Strategy. Edward Lasker

4 | | | | | ^P | | | |

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       3 | | ^B | ^P | | |^Kt | | |

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       2 | | ^P | | | | ^P | ^P | ^P |

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       1 | | | | | ^R | | ^K | |

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       A B C D E F G H

      Diag. 6.

      is, upset by one of the pieces involved being exchanged or sacrificed. An example of this is found in Diagram 6; KtxP

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       8 | | | | | | | | |

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       7 | | | | | | | #P | #K |

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       6 | #B | #P | | | | | | #P |

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       5 | | | #P | ^P |#Kt | | | |

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       4 | | | ^P | | | | | |

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       3 | | | | |^Kt | | ^B | |

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       2 | ^P | | | | | | | ^P |

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       1 | ^K | | | | | | | |

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       A B C D E F G H

      Diag. 7.

      fails on account of R X B; this leaves the Knight unprotected, and White wins two pieces for his Rook. Neither can the Bishop capture on K5 because of R X Kt. leaving the Bishop unprotected, after which BxKt does not retrieve the situation because the Rook recaptures from B6.

      A second important case, in which our simple calculation is of no avail, occurs in a position where one of the defending pieces is forced away by a threat, the evasion of which is more important than the capture of the unit it defends. In Diagram 7, for instance, Black may not play KtxP, because White, by playing P- Q6, would force the Bishop to Kt4 or B1, to prevent the pawn from Queening and the Knight would be lost. A further example of the same type is given in Diagram 8. Here a peculiar mating threat, which occurs not

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       8 | | | #B | | #Q | #R | | #K |

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       7 | | | | |#Kt | | #P | #P |

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       6 | #P |^Kt | | | | | | |

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       5 | | | ^R | |^Kt | | | |

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       4 | | | ^Q | | | | | |

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       3 | | | | | | | | |

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       2 | ^P | | | | | | ^P | ^P |

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       1 | | | | | | | ^K | |

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       A B C D E F G H

      Diag. 8.

      infrequently in practical play, keeps the Black Queen tied to her KB2 and unavailable for the protection of the B at BI.

      White wins as follows:

      1. KtxB, KtxKt; 2. RxKt, QxR; 3. Kt-B7ch, K-Kt1; 4. Kt-R6 double ch, K-R1; 5 Q-Kt8ch, RxQ; 6. Kt-B7 mate.

      We will now go a step further and turn from "acute" combinations to such combinations as are, as it were, impending. Here, too, I urgently recommend beginners (advanced players do it as a matter of course) to proceed by way of simple arithmetical calculations, but, instead of enumerating the attacking and defending pieces, to count the number of possibilities of attack and defence.

      Let us consider a few typical examples. In Diagram 9, if Black plays P-Q5, he must first have probed the position in the following way. The pawn at Q5 is attacked once and supported once to start with, and can be attacked by three more White units in three more moves (1. R-Q1, 2. R(B2)-Q2, 3. B-B2) Black can also mobilise three more units for the defence in the same number of moves (1. Kt-B4 or K3, 2. B-Kt2, 3. R-Q1). There is, consequently, no immediate danger, nor is there anything to fear for some time to come, as White has no other piece which could attack the pawn for the fifth time.

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       8 | | | | | #R | #B | #K | |

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       7 | #P | #P | | #R | | |#Kt | #P |

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       6 | | | | | | | #P | |

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       5 | | | | #P | | | | |

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       4 | | ^P | | | | | | |

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       3 | ^P |^Kt | | | | ^P | ^B | |

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       2 | | | ^R | | | | ^P | ^P |

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       1 | | | ^R | | | | ^K | |

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       A B C D E F G H

      Diag. 9.

      It would be obviously wrong to move the pawn to Q6 after White's

       R-Q1, because White could bring another two pieces to bear on the

       P, the other Rook and the Knight, whilst Black has only one more

       piece available for the defence, namely, his Rook.

      The following examples show typical