La Regola di Tarrasch è un principio generale che si applica nella maggior parte delle partite di scacchi, sia nel mediogioco che nel finale. Siegbert Tarrasch (1862-1934) formulò il principio secondo cui le torri dovrebbero essere posizionate dietro ai pedoni passati, sia che si tratti dei propri che di quelli dell'avversario. L'idea dietro alla regola è che (1) se la torre si trova dietro al proprio pedone passato, ne protegge l'avanzata, e (2) se si trova dietro un pedone passato dell'avversario, il pedone non può avanzare se non viene a sua volta protetto lungo il percorso.

La regola, esposta per la prima volta nel libro "Il gioco degli scacchi" (1938), recita testualmente:

"In complicated Rook endings the most important rule is one laid down by the author: The Rook's place is behind the passed pawn; behind the enemy pawn in order to hold it up, behind one's own in order to support its advance."^[1]

This "rule" is usually true, but not always, as there are many exceptions. Tarrasch has been quoted as saying, "Always put the rook behind the pawn.... Except when it is incorrect to do so." Template:Harvcol. Template:Algebraic notation

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 promote. A rook behind an enemy passed pawn can more readily generate counterplay.

Here are two positions to illustrate the principle.

Template:Chess diagram 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 kingside pawn structure as far as possible. If the defender wins the passed pawn, an exchange of rooks ensues and the resulting pawn ending is an easy win for the attacker.
5. At the right moment, the attacking rook abandons the pawn and joins in the attack on the kingside pawns.

The 34th game of the 1927 World Championship match between Alekhine and Capablanca is a classic example of the technique^[2] (or see annotated text). The position is after White's 54. Ra4. White won on move 82 Template:Harvcol.

Template:Chess diagram Similar positions with the rook behind the enemy passed pawn are usually a draw, but not always. The next position is after White's 35th move in the eighth game of the Henrique Mecking versus Victor Korchnoi match in 1974.^[3] White will move Ra6 as soon as possible. Black's rook is in front of his passed pawn on the a file, and the game ended in a draw on move 55 Template:Harvcol.

Template:Chess diagram In this game between Viswanathan Anand and Vladimir Kramnik from the 2007 World Chess Championship,^[4] Black's rook is in front of his passed pawn; the white rook will get behind the pawn:

36. Kf2 h5

37. g3 a5

38. Ra7

Black advanced the pawn to a2, but could do no better than to exchange the passed pawn and rook for the white rook, reaching a king and pawn endgame that ended in a draw (see stalemate) on move 65 Template:Harvcol.

Template:Chess diagram In the position from a game between Wolfgang Unzicker and Erik Lundin,^[5] White to move wins, however 48. f3+! is the only winning move. If the black pawn were still on f7, the black king could go back to f6 or g7 and the position would be a draw. (If 48. a7? Ra2+ and 49... Kf3 draws.)^[6]

Template:Chess diagram The reason this type of position 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.

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

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 tempos make the difference between winning and drawing or even losing.^[6]

Black must play very carefully to draw, rather than the very easy draw that was long thought to be the case.^[7]

Template:Chess diagram Kantorovich analyzed the position in the diagram on the right and thought that Black draws with two tempos to spare. In 2003 Steckner found an improvement for White that wins. Black's pieces are in their optimum positions: the rook is behind the a-pawn and attacking the f-pawn and the king is in its most active location. If 1. Ra8 Kf5 Black has an easy draw. However, White has a better plan which wins with precise play:

1. Kd4! (The f-pawn must be sacrificed because the rook is on a7.)

1... Rxf2

2. Rc7! Ra2

3. a7 (3. Rc6+ leads to a draw)

3... Kf5

4. Kc4!! (The old analysis was 4. Rxf7+, leading to a draw.)

4... Kg4

5. Kb3! Ra6

6. Rc4+ Kxg3

7. Ra4 Rxa7

8. Rxa7 Kxh4

9. Kc3 Kg3

10. Kd2 h4

11. Ke2 Kg2

12. Rxf7 h3

13. Rf2+ Kg3

14. Rf6 and White wins Template:Harvcol.

Template:Chess diagram small This 2008 game between Lev Aronian and Vassily Ivanchuk ended in a draw after 62 moves.^[8] The evaluation of this type of position with an extra b-pawn is still in flux as of 2010, but current theory is that it is drawish Template:Harvcol.

Template:Chess diagram small There are exceptions to the Tarrasch rule. Here are some.

• 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 Template:Harvcol.
• In the rook and pawn versus rook endgame, if the pawn is not beyond its fourth rank, the best place for the defending rook is in front of the pawn Template:Harvcol, Template:Harvcol.
• On a similar note, Cecil Purdy said that a rook is best behind its passed pawn if it is on the fifth rank or higher, or can reach those ranks. If the pawn is held up before the fifth rank, the rook is better in front of the pawn. Often the rook is best protecting the pawn from the side if it is on the fifth rank or higher Template:Harvcol.
• 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 Template:Harvcol. See the frontal defense.
• 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 cannot get his rook to the third rank for the drawing Philidor position, the defending rook draws on its first rank but loses if it is attacking the pawn from behind Template:Harvcol, Template:Harvcol.
• In the ending of a rook and two isolated pawns versus a rook, it is generally better for the stronger side to protect the pawns from the side Template:Harvcol.
• If the pawn is a rook pawn it is often better for the rook to attack it from the side, especially in a rook and pawn versus rook position Template:Harvcol. (See the Vančura position.)
• If a rook is in front of its passed pawn, it is often best for the defending rook to attack from the side. In fact, it is sometimes best to switch the defending rook from behind the pawn to the side Template:Harvcol.
• In the ending of a rook versus a pawn or pawns, the rook is best placed on its first rank Template:Harvcol, Template:Harvcol.
• When a rook is battling against pawns, if the pawns are not connected, it is often best for the rook to hold the pawns up along a rank Template:Harvcol.

Template:Chess diagram small This position from Nigel Short and Artur Yusupov in 1984^[9] is an exception to the rule, since white's king is stuck in front of the pawn Template:Harvcol. 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.

Template:Chess diagram small The position from a 1995 game between Andrei Kharlov and Alexander Morozevich^[10] is one in which the Tarrasch rule does not apply (for Black) Template:Harvcol. 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.

Template:Chess diagram small The 1993 game between Vladimir Kramnik and Alexander Beliavsky has an unusual position in which following the Tarrasch Rule is incorrect.^[11] White played 1. Ra1 and lost. 1. Rb8, abandoning the pawn so the rook can attack from behind, draws. The endgame with rooks and f- and h-pawns was analyzed to be a draw by Mikhail Botvinnik in the 1940s (with correct defense) Template:Harvcol.

Template:Chess diagram small In this 1992 game^[12] between Artur Yusupov and Jan Timman, 35. Re4! wins but 35. Ra1? in the actual game only draws. The game was drawn twenty moves later Template:Harvcol.

• Chess endgame
• Chess strategy
• Rook and pawn versus rook endgame

• Alexander Beliavsky, Modern Endgame Practice, Batsford, 2003.
• Pal Benko, The 2007 World Championship, in Chess Life, vol. 2008, n. 1, January 2008, pp. 48–49.
• Mark Dvoretsky, Dvoretsky's Endgame Manual, Russell Enterprises, 2006.
• John Emms, The Survival Guide to Rook Endings, Gambit Publications, 2008.
• Reuben Fine, Basic Chess Endings, McKay, 2003.
• James Howell, Essential Chess Endings: The tournament player's guide, Batsford, 1997.
• Victor Korchnoi, Practical Rook Endings, Olms, 2002.
• Edmar Mednis, Practical Rook Endings, Chess Enterprises, 1982.
• Edmar Mednis, Practical Endgame Tips, Cadogan Chess, 1998.
• Karsten Müller, Fundamental Chess Endings, Gambit Publications, 2001.
• Karsten Müller, How to Play Chess Endings, Gambit Publications, 2008.
• John Nunn, Understanding Chess Endgames, Gambit Publications, 2009.
• John Nunn, Nunn's Chess Endings, volume 2, Gambit Publications, 2010.
• C.J.S. Purdy, C.J.S. Purdy on the Endgame, Thinker's Press, 2003.
• Andy Soltis, Grandmaster Secrets: Endings, Thinker's Press, 2003.
• Andy Soltis, Chess to Enjoy: EGTN, in Chess Life, vol. 2010, n. 1, January 2010, pp. 42–43.

• Aron Nimzowitsch, My System, Quality Chess, 2007, pp. 115–16.

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