Tarrasch rule

From Wikipedia, the free encyclopedia

The Tarrasch rule is a general principle that applies in the majority of chess middlegames and endgames. Siegbert Tarrasch stated the "rule" that rooks should be placed behind passed pawns — either yours or your opponent's. This "rule" is usually true, but not always. Tarrasch has been quoted as saying "Always put the rook behind the pawn.... Except when it is incorrect to do so." (Soltis 2003:129).

Contents 1 Reasons 2 Illustrations 2.1 Rook behind own passed pawn — win 2.2 Rook behind enemy passed pawn — draw 2.2.1 New analysis 3 Exceptions 4 See also 5 Notes 6 References

[edit] Reasons

The advance of the passed pawn lengthens the range of a rook behind and reduces the range of a rook in front. A rook escorting a pawn from ahead must move off, potentially leaving the pawn undefended, if it is to queen. A rook behind an enemy passed pawn can more readily generate counterplay.

[edit] Illustrations

Here are two positions to illustrate the principle.

[edit] Rook behind own passed pawn — win

In the first diagram, White's rook is behind his passed pawn on the a-file, and the position is won for white.

The winning technique is straightforward:

1. Move the king towards the passed pawn. The defending king must also move that way, otherwise he will be forced to give up his rook for the pawn.
2. If the attacking king can penetrate no further because the defending king is in opposition, use tempo moves by the rook up and down the file. Once pawn moves are exhausted, then the defender runs out of options.
3. If the defending rook retreats, then advance the pawn. The defender cannot keep up this strategy. If the defending king sidesteps away from the pawn, the attacking king moves towards the pawn, and forces its advance. The defender will have to give up his rook. So the only option is for the defending king to move towards the pawn.
4. The attacking king penetrates the king-side pawn structure as far as possible. If the defender wins the passed pawn, the result is a hopeless pawn ending.
5. At the right moment, the attacking rook abandons the pawn and joins in the attack on the king-side pawns.

The final (34th) game of the 1927 world chess championship match between Alekhine and Capablanca is a classic example of the technique (see unannotated JavaScript board or annotated text).

[edit] Rook behind enemy passed pawn — draw

In the second position, White's rook is in front of his passed pawn on the a file, and the position is a draw (Korchnoi 2002:15). (The second diagram was modified.)

The reason this was long thought to be an easy draw is as follows:

1. White cannot advance his pawn to the seventh rank, because that would deprive his king of any shelter
2. So White must advance his pawn only up to the sixth, so the king can find shelter on a7
3. White's only real winning attempt was to move his king up to a7. Then he can play Rb8-b6, Kb7, a7 (threatening Ra6), forcing Black to give up his rook for the Pawn.
4. But while White is spending all this time, Black's rook can win White's kingside pawns, then advance the newly made passed pawns.
5. It has been known for White to even lose this battle of rook versus many passed pawns.
6. Thus if White tries too hard to win, he may actually lose.

[edit] New analysis

Recent theoretical analysis of this position shows that White has a strong maneuvre:

1. advance the pawn to the sixth rank
2. move the king towards the queenside
3. when the black rook takes a kingside pawn, switch the rook to guarding the pawn from the c-file, i.e. Rc7 then advance the pawn to a7.
4. Switch the white rook to the a-file with gain of tempo. Thus Black is forced to sacrifice his rook for the pawn without White having to move his king all the way to a7. These many extra tempi make the difference between winning and drawing or even losing. ^[1]

Black must play very carefully to draw, rather than the very easy draw that was long thought to be the case. ^[2]

[edit] Exceptions

There are exceptions to the Tarrasch rule. Here are some.

• In the ending of a rook and pawn versus rook, if the pawn is not beyond its fourth rank. In that case, the best place for the opposing rook is in front of the pawn (Howell 1997:38-40).

• In the ending of a rook and pawn versus a rook, where the pawn is a knight pawn (b- or g-file), the defending king is in front of the pawn, but the defender can't get his rook to the third rank for the Philidor position. In this case, the defending rook draws on its first rank but loses if it is attacking the pawn from behind (Mednis 1982:16), (Fine and Benko 2003:295).

• In the ending of a rook and pawn versus a rook, if the defending king is cut off from the pawn's file, then the best defence is with the rook on its first rank (Howell 1997:37).

• The ending of a rook versus a pawn or pawns. In this case, the rook is best placed on its first rank (Fine and Benko 2003:275-292).

• The ending of a rook and two isolated pawns versus a rook. In this case, it is generally better for the stronger side to protect the pawns from the side (Mednis 1982:29).

Yuri Averbakh said that the Tarrasch rule is usually correct when only the rooks are battling over the pawn, but when the pawn is blocked by the opposing king, the rook of the same color as the pawn is normally better protecting the pawn from the side (Emms 1999:87).

In the position from Nigel Short and Artur Yusupov in 1984, as an exception to the rule, since white's king is stuck in front of the pawn (Müller and Lamprecht 2001:199). White played 1. Rh3 (rook behind passed pawn), black replied 1. ... Kf5 and a draw resulted a few moves later. The move 1. Rf7 by White leads to a win.

The position from Kharlov-Morozevich as one in which the Tarrasch rule doesn't apply (for Black) (Emms 1999:115-16). The move 1. ...Rb7 would be in accordance with the Tarrasch rule, but 1. ... Re5 is the correct method because White's king is cut off from the pawn, White will have to spend a lot of time activating his rook, and by that time the black king will be able to get over to the queenside. The rule still applies for White, however, and the game continued:

2. Rd4 Kf6 3. Rd8 Ke7 4. Rb8 Kd7 5. Rb7+ Kc6 6. Rxf7 b4 7. Rf6+ Kb5 8. Rxg6 b3 9. Rg8 Re6 10. Rb8+ Rb6 11. Rd8 b2 12. Rd1 Rc6 13. resign, 0-1.

After 13 Kg2 Rc1 14. Rd8 b1=Q 15. Rb8+ Rb6 16. Rxb1 Rxb1 Black's king is close enough to the kingside pawns to stop them.

[edit] See also

• Chess strategy and tactics
• Endgame

[edit] Notes

[edit] References

•   John Emms (1999). The Survival Guide to Rook Endings. Everyman Chess. ISBN 1-85744-235-0.

•   Reuben Fine and Pal Benko (1941, 2003). Basic Chess Endings. McKay. ISBN 0-8129-3493-8.

•  James Howell (1997). Essential Chess Endings: The tournament player's guide. Batsford. ISBN 0-7134-8189-7.

•   Victor Korchnoi (1999, 2002). Practical Rook Endings. Olms. ISBN 3-283-00401-3.

•   Edmar Mednis (1982). Practical Rook Endings. Chess Enterprises. ISBN 93146-16-9.

•   Karsten Müller and Frank Lamprecht (2001). Fundamental Chess Endings. Gambit Publications. ISBN 1-901983-53-6.

•  Andrew Soltis (1997, 2003). Grandmaster Secrets: Endings. Thinkers' Press. ISBN 0-938650-66-1.