Lucena position

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The Lucena position, White wins.The Lucena position is one of the most famous and important positions in chess endgame theory, where one side has a rook and a pawn and the defender has a rook. It is fundamental in the rook and pawn versus rook endgame. If the side with the pawn can reach this type of position, he can forcibly win the game. Most rook and pawn versus rook endgames reach either the Lucena Position or the Philidor Position if played accurately Harvcol|de la Villa|2008|p=125.

The position is incorrectly named after the Spaniard Luis Ramirez de Lucena. The name "Lucena" is pronounced "Loo THAY na" Harvcol|Shenk|2006|p=79 in Castilian Spanish.

Introduction

The so-called "Lucena position" is named after the Spaniard Luis Ramirez de Lucena, although is something of a misnomer, because the position does not in fact appear in his book on chess, "Repetición de Amores e Arte de Axedrez" (1497). It does appear, however, in Alessandro Salvio's "Il Puttino" (1634), a romance on the career of the chess player Leonard da Cutri, and it is in that form that it is given here Harvcol|Müller|Lamprecht|2001|p=179. [http://www.chesshistory.com/winter/index.html#5534._Fischer_quote Note #5536 is about the origin]

The position is shown above and below (it should be noted that the position can be moved as a whole or mirrored so that the pawn is on any of the files b through g). White's aim is to either promote his pawn or else compel Black to give up his rook for it — either result will leave White with an overwhelming material advantage and a straightforward win. White has managed to advance his pawn to the seventh rank, but it is prevented from queening because his own king is in the way. White would like to move his king and then promote his pawn, but is prevented from moving to the a-file by the black rook, and prevented from moving to the c-file by the black king.

The essential characteristics of the position are:
* the pawn is any pawn except a rook pawn
* the pawn has advanced to the seventh rank
* the attacking king (the one with the pawn) is on the queening square of its pawn
* the attacking rook cuts off the opposing king from the pawn by at least one file
* the defending rook is on the file on the other side of the pawn

An obvious approach by White such as

: 1.Rd1+ Ke7: 2.Kc7

gets nowhere. Black can simply harass the white king with checks, and White makes no progress:

: 2. ... Rc2+: 3. Kb6 Rb2+: 4. Ka7 Ra2+: 5. Kb8

The winning method: building a bridge

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The Lucena position, White wins.In the Lucena position, white has a winning method that works for any pawn except a rook pawn (i.e. on the "a-" or "h-"file). In some circumstances, it also works for a rook pawn.

In the Lucena position above, White can win with : 1. Rd1+ Ke7: 2. Rd4!. Now, if Black plays a "waiting" move, such as : 2...Ra1 hoping to harass the white king with checks again as in the above variation, White continues : 3. Kc7 Rc1+: 4. Kb6 Rb1+: 5. Kc6 Rc1+ (or 5. Ka6 Ra1+): 6. Kb5 Rb1+ : 7. Rb4!.

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Position after 7. Rb4! Black can not prevent White from promoting the pawn.The black rook can no longer check the white king and Black cannot prevent the pawn from queening. White's shielding his king and pawn with the rook in this way is known as "building a bridge".

It is important that the white rook go initially to the fourth rank if Black uses his most active defense: repeatedly checking the white king. If Black abandons this defense, the white rook can build a bridge on the fifth rank. In the line above, after :5. Kc6 if Black moves :5... Ke6there is a trap for White: if 6. Rd5?? (to build a bridge on the fifth rank) then 6.... Rxb7! draws. However, if :6. Rd6+ Ke7:7. Rd5! and White can build a bridge on the fifth rank by getting the rook to b5, the king to b6, and then the pawn can promote Harvcol|Ward|2004|pp=48-49 (position reflected):

:7... Rc1+:8. Kb6 Rb1+:9. Rb5and White wins.

Black to move

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Position after 6. Rd5.If Black is to move in the diagramed position, he can prevent the white rook from going to the fourth rank, but then White still wins::1... Ra4:2. Rd1+ Ke7:3. Kc7 Rc4+:4. Kb6 Rb4+:5. Ka6 Rb2(The black rook is not far enough away to keep checking: if 5... Ra4+ then 6. Kb5 wins.) Now White wins by blocking the checks with:6. Rd5followed by:7. Rb5 Harvcol|Emms|1990|p=17 (position reflected).

Bridge on the fifth rank

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White to move makes a bridge on the fifth rankA bridge can also be built on the fifth rank. The main line goes:: 1. Rf5 (instead of 1. Rf4!): 1... Rc1: 2. Ke7 threatening to promote the pawn, black can just delay it with checks: 2... Re1+: 3. Kd6 Rd1+: 4. Ke6 Re1+: 5. Kd5 Rd1+: 6. Rd4and the pawn will promote. Or: 1... Kg6: 2. Ke7?! (better is 2. Rf8 Kg7 3. Rf4!, back to a bridge on the fourth rank): 2... Kxf5!: 3. d8=Q and White has a winning (but difficult) queen versus rook endgame (see pawnless chess endgames) harvcol|de la Villa|2008|pp=126-27.

Alternate plan for the defense

Alternative approaches are no better for Black. After 1. Rd1+ Ke7 2. Rd4 above, after: 2...Rb2 for example, White can still carry out his plan as above, or he can win with the simple : 3.Ra4 Kd7 : 4.Ka8 (or 4.Ka7) Kc7: 5. Rc4+chases the black king away and allows the pawn to promote (or 5. b8=Q Rxb8 6. Rc4+ wins the rook).

Rook pawn

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Silman, diagram 223
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White winsThe Lucena method also works with a rook pawn if the white rook is already on the fourth rank, the black rook isn't on the file adjacent to the pawn, and White is to move.

Otherwise, the defending king must be cut off four files from the pawn, as in the diagram. This is not a true Lucena position since the king is cut off by more than one file. White wins:: 1. Rc1 Ke7: 2. Rc8 Kd6!: 3. Rb8 Ra2: 4. Kb7 Rb2+: 5. Kc8 Rc2+: 6. Kd8 Rh2!: 7. Rb6+ Kc5: 8. Rc6+! Kxc6: 9. a8=Q+and White has a won queen versus rook endgame – one that is easier to win than one where the rook is close to its king harvcol|Silman|2007|pp=223-26.

imilar positions may be drawn

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de la Villa, position 10.4
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Black to move drawsNot all similar positions are wins. In this position, Black draws because he can safely check from the side. For this defense to work, there must be at least three files between the defending rook and the attacking king and the defending king must be so that it doesn't block the checks. That is, the defending king is on the "short side" of the pawn harvcol|de la Villa|2008|pp=127-28. (See the "short side defense" at rook and pawn versus rook endgame for more details.)

Conclusion

There is an alternate method for winning this type of position that works only for pawns on the c-file through the f-file, see Rook and pawn versus rook endgame.

Rook and pawn endgames occur quite often in chess, about eight to ten percent of all games Harvcol|de la Villa|2008|p=18, Harvcol|Emms|1999|p=6. This position is very important since endgames may simplify to it. As it is a known win, endgames sometimes revolve around the player with the pawn trying to reach the Lucena position and the other player trying to prevent it.

ee also

* Rook and pawn versus rook endgame
* Philidor position
* Chess endgame
* Chess endgame literature

Notes

References

*citation
last = de la Villa| first = Jesus
title = 100 Endgames You Must Know
publisher = New in Chess
year = 2008
id = ISBN 978-90-5691-244-4
*Citation
surname1=Emms|given1=John|authorlink1=John Emms (chess player)
year=1999
title=The Survival Guide to Rook Endings
publisher=Everyman Chess
ID=ISBN 1-85744-235-0
*Citation
surname1=Müller|given1=Karsten|authorlink1=Karsten Müller
surname2=Lamprecht|given2=Frank|authorlink2=Frank Lamprecht
year=2001
title=Fundamental Chess Endings
publisher=Gambit Publications
ID=ISBN 1-901983-53-6
*Citation
surname1=Shenk|given1=David
year=2006
title=The Immortal Game: A History of Chess
publisher=Doubleday
ID=ISBN 0-385-51010-1
*Citation
last=Silman|first=Jeremy|authorlink=Jeremy Silman
year=2007
title=Silman's Complete Endgame Course: From Beginner to Master
publisher=Siles Press
ID=ISBN 1-890085-10-3
*Citation
surname1=Ward|given1=Chris|authorlink1=Chris Ward (chess player)
year=2004
title=Starting Out: Rook Endgames
publisher=Everyman Chess
ID=ISBN 1-85744-374-8

Further reading

* citation
last = Dvoretsky| first = Mark| authorlink = Mark Dvoretsky
year = 2006
title = Dvoretsky's Endgame Manual
edition = second
publisher = Russell Enterprises
id=ISBN 1-888690-28-3
*citation
last1=Fine |first1=Reuben |authorlink1=Reuben Fine
last2=Benko |first2=Pal |authorlink2=Pal Benko
title = Basic Chess Endings
publisher = McKay
year = 1941, 2003
id = ISBN 0-8129-3493-8 The Lucena position is diagram 307 in the first edition and diagram 623 in the second edition.

*Citation
last = Korchnoi|first=Victor|authorlink = Victor Korchnoi
title = Practical Rook Endings
publisher = Olms
year = 1999, 2002
id = ISBN 3-283-00401-3

* Citation
surname1=Minev|given1=Nikolay|authorlink1=Nikolay Minev
year=2004
title=A Practical Guide to Rook Endgames
publisher=Russell Enerprises
ID=ISBN 1-888690-22-4
* Roycroft, John (1972). "Test Tube Chess", Faber. diagram 80 is the Lucena position

*Citation
surname1=Speelman|given1=Jon|authorlink1=Jon Speelman
surname2=Tisdall|given2=Jon|authorlink2=Jonathan Tisdall
surname3=Wade|given3=Bob|authorlink3=Robert Wade (chess player)
title=Batsford Chess Endings
year=1993
publisher=B. T. Batsford
ID=ISBN 0-7134-4420-7

External links

* [http://www.chessvideos.tv/lucena-position.php Interactive Endgame Simulation of the Lucena Position]
* [http://www.chess-videos.com/forum/about356.html Video explaining the Lucena Position]
* [http://www.geocities.com/lifemasteraj/lucena_1.html A.J.'s lesson on Lucena position]