British problem solving championship – solutions

by John Nunn
3/5/2014 – We recently reported on this championship, which was won by our favourite author Dr John Nunn, who selected four highly entertaining problems from the competition for our readers to solve. Today John provides the solutions – annotated in his inimitable clear and precise style. Even if you are not a problem enthusiast you can, with his help, enjoy a very special section of chess.

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British Chess Problem Solving Championship

By John Nunn

The format of the British Solving Championship has remained the same for many years. There are six sessions on one day, with each session confronting solvers with problems of one specific type. The first round consists of three two-movers and all the top solvers negotiated them without mistakes. Here’s one which you might like to try to solve yourself. The solutions to the problems will be given in a few days.

If you want to try the problem under tournament conditions allow yourself eight minutes to find the solution. This problem is slightly tricky because the composer has made an effort to deceive the solver.

[Event "Die Neue Zeitung"] [Site "?"] [Date "1951.??.??"] [Round "?"] [White "Grasemann, Herbert"] [Black "White to play and mate in two"] [Result "1-0"] [Annotator "Nunn,John"] [SetUp "1"] [FEN "4R2b/2Npr3/r7/1p6/3kN2Q/1PR5/3p2K1/B7 w - - 0 1"] [PlyCount "3"] [EventDate "1951.??.??"] {The solution involves abandoning the checking lines (with Black to play given below) by playing} 1. Qg5 {This move takes away the black king's flight on e5 but in compensation gives a new one on e4. The rook moves which previously checked the white king now prevent the threat by pinning White's queen, but they lead to different mates.} ({If we assume that Black is to play in the diagram, there are already some attractive variations; for example} 1. -- Rg6+ 2. Rg3#) (1. -- Rg7+ 2. Ng5#) (1. -- Ke5 2. Rc5# {It looks as though these lines should be part of the solution, so it's tempting to try to preserve them. However, it soon becomes apparent that it is difficult to create a threat while keeping the checking variations intact and in addition black has strong defences such as ...Rxa1.}) 1... Kxe4 (1... -- 2. Qd5#) (1... Rg6 {or 1...Rd6} 2. Re3#) (1... Rg7 2. Nxb5#) (1... Re5 {or 1...Be5} 2. Qe3#) 2. Re3# 1-0

Here is one of the two studies, and to simulate the tournament conditions you should allow yourself half an hour to find the solution. Although White’s moves are all checks, the study proved quite challenging and only seven of the competitors managed to get it completely correct.

[Event "1st Prize, Schach-Echo"] [Site "?"] [Date "1964.??.??"] [Round "?"] [White "Heuäcker, Paul"] [Black "White to play and win"] [Result "1-0"] [Annotator "Nunn,John"] [SetUp "1"] [FEN "7Q/3q4/3p3N/2p2n2/8/7k/8/6K1 w - - 0 1"] [PlyCount "15"] [EventDate "1964.??.??"] 1. Ng8+ $1 {This is the correct first move. Again and again Black's options are restricted by the possibility of a knight fork on f6.} (1. Nxf5+ {looks like the obvious first move, especially as it sets up a potential skewer if the black king takes the knight later on. However, although White can give a lot of checks he cannot win the game; for example,} Kg4 2. Qh4+ Kf3 3. Qh3+ Kf4 4. Qe3+ Kg4 5. Qg3+ Kh5 6. Qh3+ Kg5 7. Qh6+ Kg4 {and White is going round in circles.}) 1... Nh4 ({After} 1... Kg3 2. Qh2+ Kf3 3. Qf2+ {the fork on f6 follows next move.}) 2. Qc3+ Nf3+ 3. Qxf3+ Kh4 {I reached this point in the solution quite quickly, but for some time I could not see how to proceed. At first, I was convinced that White would have to play a non-checking move, but then I saw that the Nf6+ fork is so strong that White can win with the correct sequence of checks.} 4. Qf2+ (4. Qh1+ $2 {fails to} Qh3) ({while the tempting} 4. Nf6 $2 Qg7+ 5. Kf2 Kg5 6. Ne4+ Kg6 7. Qg4+ Kh7 {doesn't lead anywhere.}) 4... Kg5 (4... Kh3 5. Qh2+ {wins at once.}) 5. Qe3+ Kg6 (5... Kh4 6. Qh6+ Kg3 7. Qh2+ Kf3 8. Qf2+ {with the usual fork to come next move.}) 6. Qh6+ Kf7 7. Qh7+ Ke6 ({Or} 7... Ke8 8. Nf6+) 8. Qh3+ {and Black finally loses his queen to a skewer.} 1-0

The fourth round, consisting of two helpmates, proved exceptionally difficult and provided the problemists with their revenge on the over-the-board players. One helpmate was completely straightforward, but the other proved so difficult that only three competitors, Dolf Wissmann, Eddy van Beers and helpmate expert Michael McDowell, scored at all on it.

In a helpmate, Black moves first and both sides cooperate to help White mate Black. Thus in this helpmate both players make five moves with Black starting and White delivering mate with his final move.

[Event "Original for Die Schwalbe"] [Site "?"] [Date "2014.??.??"] [Round "?"] [White "Arnold, Randolf"] [Black "Helpmate in five moves"] [Result "*"] [Annotator "Nunn,John"] [SetUp "1"] [FEN "4n1n1/4r1p1/3pqpKp/3rbp1p/3k1B2/8/5P2/8 b - - 0 1"] [PlyCount "10"] [EventDate "1977.??.??"] {In a helpmate such as this it is very often a case of you either see the idea or you don't. There are various possible mating positions, but the congested arrangement of black pieces makes them hard to achieve. One example is to have the black king on e5, the white bishop on e3 and mate by f4, but for this a black piece has to block e4. It turns out that it's impossible for White to capture the pawn on f6 and come back to e3 with his bishop in time to allow a black knight to reach e4 via f6. I had the idea to mate the king on e6 by exf5 or gxf5, with the white pawn taking a black piece on the e-file or the g-file on the way. However, I couldn't see how to arrange this while retaining control of e5. The crucial idea, which I overlooked, is to sacrifice the white bishop on e5 so as to block the crucial square with a black pawn. The solution runs} 1... Qd7 2. Bh2 Bg3 3. fxg3 Ke5 4. g4+ Ke6 5. Be5 fxe5 6. gxf5# *

The last round involved two selfmates to solve in 30 minutes. One was relatively straightforward, so everything depended on the longer selfmate.

In a selfmate, White is trying to commit suicide by forcing Black to mate him, while Black is doing everything in his power to avoid this. White moves first and his aim is to force Black to deliver mate on Black’s fourth move.

[Event "3rd Prize, Northwest Chess 78-9"] [Site "?"] [Date "1978.??.??"] [Round "?"] [White "Gedda, Bertil"] [Black "Selfmate in four moves"] [Result "*"] [Annotator "Nunn,John"] [SetUp "1"] [FEN "7R/8/3p1p2/3B4/2Np4/3P1nKb/8/2QR2nk w - - 0 1"] [PlyCount "8"] [EventDate "1978.??.??"] {When you see a problem in which Black has only one legal move, it's tempting to think that the solution will be easy, but that may not be the case. In this position, all three black pieces are pinned and his only mobile unit is the f-pawn. However, it is not at all obvious how Black is going to mate White as the white king is not especially confined, being able to move to both f2 and f4. If White at any stage unpins the knight on f3 or the bishop on h3, then that piece would have a choice of squares to move to, which makes it unlikely that White will be able to force Black to deliver mate. The knight on g1 is a different matter, as it has only one available square and that square checks the white king. The problem then is to prevent the white king from moving to f2, f3 or h3. I saw that it was possible to deal with the square f2 by playing Ne3 at a moment when Black would be forced to reply ...dxe3. However the f3- and h3-squares looked like more of a problem. Then it suddenly occurred to me that if White started with 1 Qg5 and Black took the queen then the pawn would be forced to advance to g4, covering the remaining two awkward squares. All the pieces were coming together now and I quickly saw the line} 1. Qg5 fxg5 { This line was so attractive that I was convinced I had found the correct basic idea.} ({The only remaining problem was to deal with the reply} 1... f5 {This stumped me for a while as it seemed that White is faced with the same problem of controlling the squares f3 and h3. At the last moment I realised that these problems might disappear if White moved his king and after I played the moves} 2. Kf4 Kh2 {on the board, the final piece of the puzzle leapt out at me and with just a few seconds to go I wrote down the continuation} 3. Qg3+ Kh1 4. Ne5 dxe5#) 2. Re1 g4 3. Ne3 dxe3 4. Re2 Nxe2# *

The event was generously sponsored by investment managers Winton Capital, and I would like to thank them, Eton College and the British Chess Problem Society for providing an entertaining day of solving.


Topics Nunn, Problems

Dr John Nunn (born 1955) is an English grandmaster, author and problem-solver. He was among the world’s leading grandmasters for nearly twenty years, winning four gold medals in chess Olympiads, and is a much-acclaimed writer whose works have won ‘Book of the Year’ awards in several countries. In 2004, 2007 and 2010, Nunn was crowned World Chess Solving Champion. Now 62, he continues to compete successfully in over-the-board and problem-solving events.
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