The Tarrasch rule is a general principle that applies in the majority of chess

Chess

Chess is a two-player board game played on a chessboard, a square-checkered board with 64 squares arranged in an eight-by-eight grid. It is one of the world's most popular games, played by millions of people worldwide at home, in clubs, online, by correspondence, and in tournaments.Each player...

 middlegames and endgames. Siegbert Tarrasch

Siegbert Tarrasch

Siegbert Tarrasch was one of the strongest chess players and most influential chess teachers of the late 19th century and early 20th century....

 (1862–1934) stated the "rule" that rooks

Rook (chess)

A rook is a piece in the strategy board game of chess. Formerly the piece was called the castle, tower, marquess, rector, and comes...

 should be placed behind passed pawn

Passed pawn

In chess, a passed pawn is a pawn with no opposing pawns to prevent it from advancing to the eighth rank, i.e. there are no opposing pawns in front of it on the same file nor on an adjacent file. A passed pawn is sometimes colloquially called a passer...

s – either yours or your opponent's. The idea behind the guideline is that (1) if a player's rook is behind his passed pawn, the rook protects it as it advances, and (2) if it is behind an opponent's passed pawn, the pawn cannot advance unless it is protected along its way.
The original quote, from page 57 of his book The Game of Chess (1938) is

"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."

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." .

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

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 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

World Chess Championship 1927

The 1927 World Chess Championship was played between José Raúl Capablanca and Alexander Alekhine. It was played in Buenos Aires from September 16 to November 29, 1927...

 match between Alekhine

Alexander Alekhine

Alexander Alexandrovich Alekhine was the fourth World Chess Champion. He is often considered one of the greatest chess players ever.By the age of twenty-two, he was already among the strongest chess players in the world. During the 1920s, he won most of the tournaments in which he played...

 and Capablanca

José Raúl Capablanca

José Raúl Capablanca y Graupera was a Cuban chess player who was world chess champion from 1921 to 1927. One of the greatest players of all time, he was renowned for his exceptional endgame skill and speed of play...

 is a classic example of the technique (or see annotated text). The position is after White's 54. Ra4. White won on move 82 .

Rook behind enemy passed pawn: usually a draw

Similar positions with the rook behind the enemy passed pawn are usually a draw

Draw (chess)

In chess, a draw is when a game ends in a tie. It is one of the possible outcomes of a game, along with a win for White and a win for Black . Usually, in tournaments a draw is worth a half point to each player, while a win is worth one point to the victor and none to the loser.For the most part,...

, but not always. The next position is after White's 35th move in the eighth game of the Henrique Mecking

Henrique Mecking

Henrique Mecking was a leading Brazilian chess Grandmaster in the 1970s. He was a very strong player at an early age , drawing comparisons to Bobby Fischer, although he did not achieve the International Grandmaster title until 1971...

 versus Victor Korchnoi match in 1974. 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 .
In this game between Viswanathan Anand

Viswanathan Anand

V. Anand or Anand Viswanathan, usually referred as Viswanathan Anand, is an Indian chess Grandmaster, the current World Chess Champion, and currently second highest rated player in the world....

 and Vladimir Kramnik

Vladimir Kramnik

Vladimir Borisovich Kramnik is a Russian chess grandmaster. He was the Classical World Chess Champion from 2000 to 2006, and the undisputed World Chess Champion from 2006 to 2007...

 from the 2007 World Chess Championship, 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

Stalemate

Stalemate is a situation in chess where the player whose turn it is to move is not in check but has no legal moves. A stalemate ends the game in a draw. Stalemate is covered in the rules of chess....

) on move 65 .
In the position from a game between Wolfgang Unzicker

Wolfgang Unzicker

Wolfgang Unzicker was one of the strongest German chess Grandmasters from 1945 to about 1970.He decided against making chess his profession, choosing law instead....

 and Erik Lundin

Erik Lundin

Erik Lundin a Swedish chess master.In 1928, he won in Oslo, took 5th in Helsingborg, tied for 2nd-3rd in Stockholm . In 1929, he took 2nd in Göteborg , and took 3rd in Västerås...

, 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.)

New analysis

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.

Black must play very carefully to draw, rather than the very easy draw that was long thought to be the case.
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 an 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 .

This 2008 game between Lev Aronian and Vassily Ivanchuk ended in a draw after 62 moves. 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 .

Exceptions

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

• 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 , .

• On a similar note, Cecil Purdy
  Cecil Purdy
  Cecil John Seddon Purdy was an Australian chess International Master and inaugural World Correspondence Chess champion. Purdy earned the Grandmaster title at Correspondence Chess in 1953...
  
   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 .

• 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 . 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
  Philidor position
  The Philidor position usually refers to an important chess endgame which illustrates a drawing technique when the defender has a king and rook versus a king, rook, and a pawn. It is also known as the third rank defense, because of the importance of the rook on the third rank cutting off the...
  
  , the defending rook draws on its first rank but loses if it is attacking the pawn from behind , .

• In the ending of a rook versus a pawn or pawns, the rook is best placed on its first rank , .

• In the ending of a rook and two isolated pawn
  Isolated pawn
  In chess, an isolated pawn is a pawn which has no friendly pawn on an adjacent file. An isolated queen's pawn is often called an isolani. Isolated pawns are usually a weakness because they cannot be protected by other pawns...
  
  s versus a rook, it is generally better for the stronger side to protect the pawns from the side .

• 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 . (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 .

• Yuri Averbakh
  Yuri Averbakh
  Yuri Lvovich Averbakh is a Soviet and Russian chess player and author. He is currently the oldest living chess grandmaster.-Life and career:...
  
   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 .

Short vs. Yusupov

In the position from Nigel Short

Nigel Short

Nigel David Short MBE is an English chess grandmaster earning the title at the age of 19. Short is often regarded as the strongest English player of the 20th century as he was ranked third in the world, from January 1988 – July 1989 and in 1993, he challenged Garry Kasparov for the World Chess...

 and Artur Yusupov

Artur Yusupov

Artur Mayakovich Yusupov is a German International Grandmaster of chess, and a chess writer.-Chess career:...

 in 1984, as an exception to the rule, since white's king is stuck in front of the pawn . 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.

Kharlov vs. Morozevich

The position from a 1995 game between Andrei Kharlov

Andrei Kharlov

__FORCETOC__Andrei Kharlov is a Russian chess player. In 1992, he received the title of Grandmaster after tying for first place in the 1990 Russian National Championships. Since then, Kharlov has won the 1996 Eurocup and the 1998 Russian Club Cup with the Kazan chess team...

 and Alexander Morozevich

Alexander Morozevich

Alexander Morozevich is a Russian chess Grandmaster. In the November 2011 FIDE list, he had an Elo rating of 2762, making him the 9th-highest rated player in the world, although he has previously ranked as high as second, in the July 2008 list....

 is one in which the Tarrasch rule does not apply (for Black) . 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.

Kramnik vs. Beliavsky

The 1993 game between Vladimir Kramnik

Vladimir Kramnik

Vladimir Borisovich Kramnik is a Russian chess grandmaster. He was the Classical World Chess Champion from 2000 to 2006, and the undisputed World Chess Champion from 2006 to 2007...

 and Alexander Beliavsky

Alexander Beliavsky

-External links:...

 has an unusual position in which following the Tarrasch Rule is incorrect. White played 1. Ra1 and lost. Interestingly, 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

Mikhail Botvinnik

Mikhail Moiseyevich Botvinnik, Ph.D. was a Soviet and Russian International Grandmaster and three-time World Chess Champion. Working as an electrical engineer and computer scientist at the same time, he was one of the very few famous chess players who achieved distinction in another career while...

 in the 1940s (with correct defense) .

Yusupov vs. Timman

In this 1992 game between Artur Yusupov

Artur Yusupov

Artur Mayakovich Yusupov is a German International Grandmaster of chess, and a chess writer.-Chess career:...

 and Jan Timman

Jan Timman

Jan Timman is a Dutch chess Grandmaster who was one of the world's leading players from the late 1970s to the early 1990s. At the peak of his career he was considered to be the best non-Soviet player and was known as "The Best of the West"...

, 35. Re4! wins but 35. Ra1? in the actual game only draws. The game was drawn twenty moves later .