Chess Problems: The Self-block Put to Bed

3/27/2012 – This popular theme in problem chess – a piece on the defending side blocks a flight square of the king, thus enabling the attacker to mate – is also seen in normal games. In its pure form, or as a weakening with a delayed effect, examples on a par with composed problems are rare. Our problem expert David Friedgood asked our readers to look for OTB self-blocks. Here are some results.

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The Self-block Put to Bed

By David Friedgood

In the preceding article on the self-block theme, I tightened up the requirements for the best examples of games in which self-blocks played a part. [Definition of self-block: a unit on the defending side moves to a square to which the defending king could otherwise move, enabling the attacker to deliver checkmate]. Examples fulfilling these revised requirements proved very difficult to find.

Greek IM Ilias Kourkounakis sent me a selection of positions from his stock that he uses for training. He doubts that examples fitting my requirements are even out there to be found. Amongst his examples is the following one, which probably has a number of precursors of a similar nature. It is a neat illustration of what I call ‘impure’ self-blocks, that is, those which are produced not only for reasons of self-blocking, but have another motive as well:

[Event "Irkutsk"] [Site "Irkutsk"] [Date "1961.??.??"] [Round "?"] [White "Kopylov"] [Black "Karlson"] [Result "0-1"] [Annotator "David Friedgood"] [SetUp "1"] [FEN "3r2k1/1p4pp/2p5/pnP2b2/2K2N1P/P4P2/5BP1/7R b - - 0 1"] [PlyCount "3"] [EventDate "1961.??.??"] [EventCountry "URS"] {If the knight weren't guarding e6, then 1...Be6 would be mate.} 1... Rd3 $1 { With a double threat.} 2. Nxd3 (2. Rc1 Nxa3#) (2. Ra1 Rc3#) 2... Be6# {The knight has not only blocked d3, but has been decoyed from guarding e6. Such 'impure' double motivations for the move eliciting the self-block seem to characterise most self-blocks in games.} 0-1

Steven B Dowd, whose reviews appear quite often on this site and who is an accomplished problem composer as well, also sent me a few examples. After I strengthened the requirements though, he pointed out that it would be very difficult to search electronically for anticipatory self-blocks (a self-block which occurs some moves before the opponent takes advantage of it). This is a challenge in itself!

Michael McDowell, who is even better known in the problem world as a composer than as a former British champion solver, has an exceptional memory. He suggested a few pertinent games by historic personalities such as Joseph Henry Blackburne, of which the following one is perhaps the most interesting from a thematic point of view, with two self-blocks arising perfectly naturally:

[Event "San Remo"] [Site "San Remo"] [Date "1930.??.??"] [Round "?"] [White "Bogoljubow, Efim"] [Black "Monticelli, Mario"] [Result "0-1"] [ECO "E13"] [Annotator "David Friedgood"] [PlyCount "78"] [EventDate "1930.??.??"] [EventRounds "15"] [EventCountry "ITA"] [Source "ChessBase"] [SourceDate "1999.07.01"] 1. d4 Nf6 2. c4 e6 3. Nc3 Bb4 4. Nf3 b6 5. Bg5 Bxc3+ 6. bxc3 Bb7 7. e3 d6 8. Bd3 Nbd7 9. O-O Qe7 10. Nd2 h6 11. Bh4 g5 12. Bg3 O-O-O 13. a4 a5 14. Rb1 Rdg8 15. f3 h5 16. e4 h4 17. Be1 e5 18. h3 Nh5 19. c5 dxc5 20. d5 Nf4 21. Nc4 Rh6 22. Rf2 f5 23. d6 Rxd6 24. Nxd6+ Qxd6 25. Bc4 Rf8 26. exf5 Rxf5 27. Rd2 Qe7 28. Qb3 Rf8 29. Bd3 e4 30. Bxe4 Bxe4 31. fxe4 Qxe4 32. Qc2 Qc6 33. c4 g4 {The final onslaught begins. This cracks open the white king's position, but preparatory moves like 33...Ne5 or 33...Qe6 were also good.} 34. Bxh4 gxh3 35. g3 (35. Bg3 {would have been tougher, but one can understand Bogoljubow's desire to keep the g file closed. The move played turns out to be a self-block later on.}) 35... Ne5 $1 {This leaves White completely without a defence.} 36. Rb3 {Allowing a forced mate.} Ne2+ 37. Rxe2 {The second self-block arrives.} Rf1+ 38. Kxf1 Qh1+ 39. Kf2 Ng4# {[#]A quite often seen queen and knight mating configuration, somewhat spoiled by the pawn on h3, which is now surplus to requirements. The two self-blocks are both anticipatory, the g3 self-block occurring four moves before the mate and the e2 self-block two moves in advance.} 0-1

An example of the kind of thing I have been looking for occurred in a game I played against my good friend Craig Pritchett, the Scottish IM and author, some years ago.

[Event "4NCL"] [Site "London"] [Date "1999.01.24"] [Round "?"] [White "Friedgood, David"] [Black "Pritchett, Craig"] [Result "1-0"] [Annotator "David Friedgood"] [SetUp "1"] [FEN "r3r1k1/1p1b1pp1/1bpp1q1p/p3pP1Q/2PnP2N/3P2PP/PP4BK/1RB2R2 w - - 0 20"] [PlyCount "19"] [EventDate "2012.??.??"] {Craig had just erred with 19...Bc5-b6, whereas 19...Nc2! would probably have ensured at least equality, as he pointed out immediately after the game. Now the white attack is too strong.} 20. g4 Bd8 {The self-blocking move! I had realised that this gave me an opportunity for a nice combination.} 21. g5 $1 hxg5 22. Ng6 fxg6 23. fxg6 Nf5 (23... Ne6 {giving up the queen would have prolonged the game but not altered the result.}) 24. Bxg5 {Continuing with the planned coup. Of course there are other wins, but I only had eyes for the self-block combination.} Qxg5 25. Qh7+ Kf8 26. Rxf5+ Bxf5 27. Qh8+ Ke7 28. Qxg7+ {Finally taking advantage of the self-block 8 moves after it occurred, as the king can't escape to d8. Now it is mate next move after} Ke6 29. Qf7# { Craig resigned. It must be noted, though, that the self-block does not occur in the actual mating position, so my requirement is not strictly fulfilled by this example. I shall continue to keep watch in the hope of spotting a better case of an anticipatory self-block in a game!} 1-0

To put the self-block theme to bed for the time being (doubtless it will crop up many times in future articles), here are a couple of problems for solving, with self-blocks central to the composer’s idea. The solutions will be given next week.

    Mate in two

You have to find White’s first (‘key’) move, which is the only one to force mate on the following move whatever Black tries to do about it. This move will threaten mate and all Black’s defences will create some weakness – mostly self-blocks, which White can take advantage of to deliver mate. In this case, most moves by the knight on d5 will threaten 2. Rf4# (now that d5 is guarded), but which is the correct one?

    Mate in three

You have to find White’s key move, which will threaten to force mate in a further two moves. Again, Black’s defences to the threat will allow White to meet them with continuations that take advantage of the weaknesses they create – again self-blocks, but this time of the anticipatory variety (see commentary above). Three-movers are generally more difficult than two-movers, but this one is not so bad – all the white moves after the key are checks. You could also ask yourself: Is the Bh3 really needed to guard e6?

Any queries or constructive comments can be addressed to the author at

Copyright in this article David Friedgood 2012/ChessBase

The British Chess Problem Society (BCPS), founded in 1918, is the world's oldest chess problem society. It exists to promote the knowledge and enjoyment of chess compositions, and membership is open to chess enthusiasts in all countries.

The Society produces two bi-monthly magazines, The Problemist and The Problemist Supplement (the latter catering for beginners), which are issued to all members. Composers from all over the world send their problems and studies to compete in the tourneys run by the society.

The BCPS also organises the annual British Chess Solving Championship, and selects the Great Britain squad for the World Chess Solving Championship. The Society holds an annual residential weekend, with a full programme of solving and composing tourneys and lectures; this event attracts an international participation. Members are also entitled to use the resources of the BCPS library, and the Society book service, which can provide new and second-hand publications.

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