Philidor position

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Philidor, 1777
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White wins with either side to movePhilidor studied many endgame positions. Another one that he studied in 1777 (and is also called "Philidor's Position") involves a queen versus a rook (see the diagram).

If Black is to move in this position, he quickly loses his rook by a fork (or gets checkmated). For example,

: 1. ... Rb1: 2. Qd8+ Ka7: 3. Qd4+ Ka8: 4. Qh8+ Ka7: 5. Qh7+

If White is to move in this position, he would like to be in this position except with Black to move. This can be accomplished by triangulation:

: 1. Qe5+ Ka8: 2. Qa1+ Kb8: 3. Qa5and now it is back to the same position but Black has to move (and is in Zugzwang)Harvcol|Nunn|2002|pp=50-51, Harvcol|Müller|Pajeken|2008|p=178. Nunn describes that with the pieces in the center of the board the queen ought to force the rook towards the "Philidor position". Nunn describes the various retreat positions for the rook, the "fourth, third, second" rank defenses, then the "Philidor position". The rook can be won in fewer than fifty moves, avoiding the fifty move rule.

Rook and bishop versus rook

Chess diagram|=
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Philidor, 1749
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White to move wins.Another famous position studied by and named after Philidor is in the ending of a rook and bishop versus a rook (diagram). White wins because his king has reached the sixth rank and black's king is poorly placed (opposite the white king) Harvcol|Howell|1997|pp=148-50. If this type of position arises, it is usually because of inferior defense. Nevertheless, it is tricky to win harvcol|Nunn|2007|p=163.

The winning method is as follows:: 1. Rf8+! Re8: 2. Rf7!

threatening to switch to the other side and checkmate.

: 2. ... Re2

If 2...Re3 3.Rb7. If now 3...Kc8 4.Ra7 and checkmate on a8, else black loses the rook because the bishop covers b3 (one of the reasons white wants to force the black rook to the third rank). If 3...Rc3 5.Rd7+ and white has achieved the position at move 8 below, only some moves faster. Other second moves for black lose faster : 2...Rh8. 3.Ra7 Rh6+ 4.Be6 with checkmate or loss of rook. 2...Kc8 3.Ra7 Rd8+ 4.Kc6 Kb8 5.Rb7+ Ka8 (5...Kc8 6.Be6+) 6. Rb1 Ka7 (6...Rc8+ 7.Kd7+) 7. Kc7 with checkmate or loss of rook to follow. Correct bishop moves are required for White to win.

: 3. Rh7 Re1: 4. Rb7

The winning line only works if the white rook is on b7 or f7.

: 4. ...Rc1

Or 4...Kc8 5.Ra7 Rb1 6.Rf7 Kb8 7.Rf8+ Ka7 8.Ra8+. White wins because the chessboard has only eight files.

: 5. Bb3

This is the key idea. It forces the black rook to the inferior third rank while preventing 5...Rd1+. Black is in zugzwang.

: 5. ... Rc3

If instead 5...Kc8 then 6.Rb4 Kd8 7.Rf4 Re1 (or 7...Kc8 8.Bd5 Kb8 9.Ra4) 8.Ba4 Kc8 9.Bc6 Rd1+ 10.Bd5 Kb8 11.Ra4. Now White completes the following maneuvers, getting the bishop back to d5 with gain of tempo.

: 6. Be6 Rd3+: 7. Bd5! Rc3: 8. Rd7+ Kc8

If 8...Ke8 then 9.Rg7 and checkmate on g8 next move, else loss of rook since the bishop covers f3.

: 9. Rh7 Kb8: 10. Rb7+ Kc8: 11. Rb4 Kd8

If 11...Rd3 12.Ra4 and checkmate or loss of rook since the bishop covers b3.

: 12. Bc4

Stopping the check on d3 and cutting off the rook entirely.

: 12. ... Kc8: 13. Be6+ Kd8: 14. Rb8+

and checkmate next move Harvcol|Howell|1997|pp=148-50, harvcol|Nunn|2007|pp=163-64, Harvcol|Müller|Pajeken|2008|p=178.

This is an exercise in domination of the king. Interestingly, many of the longest games on record involve this endgame. [ [http://www.xs4all.nl/~timkr/records/records.htm#Longest%20game Chess records by Tim Krabbé ] ]

ee also

* Chess endgame
* Rook and pawn versus rook endgame
* Lucena position - a winning position, in contrast to the Philidor position for rook and pawn versus rook
* Cochrane Defense - a drawing position, in contrast to the Philidor position for rook and bishop versus rook
* Computer chess "endgame tablebase" section has queen versus rook played by computer versus human
* 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=Howell|given1=James|authorlink1=
year=1997
title=Essential Chess Endings: The tournament player's guide
publisher=Batsford
ID=ISBN 0-7134-8189-7

*Citation
surname1=Müller|given1=Karsten|authorlink1=Karsten Müller
surname2=Pajeken|given2=Wolfgang
year=2008
title=How to Play Chess Endings
publisher=Gambit Publications
ID=ISBN 978-1-904600-86-2

*Citation
surname1=Nunn|given1=John|authorlink1=John Nunn
year=1999
title=Secrets of Rook Endings
publisher=Gambit Publications
ID=ISBN 1-901983-18-8

*Citation
surname1=Nunn|given1=John
year=2002
title=Secrets of Pawnless Endings
publisher=Gambit Publications
ID=ISBN 1-901983-65-X

* Citation
surname1=Nunn|given1=John
title=Secrets of Practical Chess
year=2007
edition = second
publisher=Gambit Publications
ID=ISBN 978-1-904600-70-1

Further reading

* citation
last = Dvoretsky| first = Mark| authorlink = Mark Dvoretsky
year = 2006
title = Dvoretsky's Endgame Manual
edition = 2nd
publisher = Russell Enterprises
id=ISBN 1-888690-28-3
* citation
last = Emms
first = John
authorlink= John Emms (chess player)
title = The Survival Guide to Rook Endings
publisher = Everyman Chess
year = 1999
id = ISBN 1-85744-235-0
*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
*Citation
last=Flear|first=Glenn|authorlink=Glenn Flear
year=2007
title=Practical Endgame Play - beyond the basics: the definitive guide to the endgames that really matter
publisher=Everyman Chess
ID=ISBN 978-1-85744-555-8
pages=28-29
*citation
last = Korchnoi|first=Victor|authorlink = Victor Korchnoi
title = Practical Rook Endings
publisher = Olms
year = 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
*citation
last1=Müller |first1= Karsten |authorlink1=Karsten Müller
last2=Lamprecht |first2=Frank |authorlink2 = Frank Lamprecht
title = Fundamental Chess Endings
publisher = Gambit Publications
year = 2001
id = ISBN 1-901983-53-6
* citation
last = Ward | first = Chris |authorlink=Chris Ward
title = Starting Out: Rook Endgames
publisher = Everyman Chess
year = 2004
id = ISBN 1-85744-374-8

External links

* [http://www.chessvideos.tv/philidor-position.php Interactive Endgame Simulation of the Philidor Position]
* [http://www.chessvideos.tv/forum/about365.html Video explaining the Philidor Position]