ChessBase 2015 New Year's Puzzle Contest
We trust that you have enjoyed solving our 2014 Christmas puzzles, which
were published from December 25 to 31. If you were meditating in a cave
in the Hindu Kush mountains during that week and missed them, do not worry:
you can review the problems by clicking on the images below, which will
take you to specific installments.
Now to our puzzle challenge. We give you three full weeks to solve the
following problems – and perhaps win a very nice prize. This will
consist of recent ChessBase software, with autographs of top players –
at least one a World Champion or ex. And the first prize will probably come
with a personal dedication. Note that we have selected puzzles that are
not easily accessible to computer solving. What is the point in giving positions
that modern chess engines solve in their first seconds of thought? Note
too that by some freak accident of the Universe all three problems were
provided to us by puzzle king John Nunn.

This is a picture from 1983 of John Nunn composing a problem in my living
room during a visit in Germany. Today, over 31 years later, he still supplies
my family with chess and mind sport puzzles.
Puzzle one: How can it be a draw?
This is a nice little problem I received from John in 2001. It is one of
those typical Nunn things that require no diagram to formulate:
White has a king, a queen and two pawns against
Black's bare king.
It is White to move, but he cannot force a win. The game is drawn.
Can
you reconstruct the position? The problem has an additional stipulation
"White is not stalemated". If it didn't the position
on the right would be a possible solution.
Out of curiosity (and not as part of today's task) you may want to think
about how much material White can have against the bare black king, be on
the move and still not be able to win. Once again: White is not stalemated
and can acutally make moves. Prepare to be surprised.
Puzzle two: en passant mate
Many
years ago my sons were playing a game of chess against each other. Suddenly
one came to me to complain that the other was cheating: "He wants to
take a pawn from a square I didn't move it to!" I patiently explained
to him that if a pawn moves two ranks forward from its starting position,
and an enemy pawn could have captured it had the pawn moved only one square
forward, then it can capture the pawn "en passant" (in passing),
exactly as if the pawn had moved only one square forward and the enemy pawn
had captured it normally. But it could only do so immediately after double-rank
move was made.
The face of my son reminded me of the Prince George in the first 40 seconds
of this Blackadder clip. "You
are joking, right?" he said, and then, sarcastically: "This rule
applies on every day of the week?"
The en passant rule was one of the last major changes in European chess,
and occurred between 1200 and 1600. The motivation was to prevent the newly
added two-square first move for pawns from allowing a pawn to evade capture
by an enemy pawn.
And en passant capture occurs in a line of the French advicated by Steinitz
(1.e4 e6 2.e5 d5 3.exd6 e.p.) and a main line of the Petroff (1.e4 e5 2.Nf3
Nf6 3.d4 exd4 4.e5 Ne4 5.Qxd4 d5 6.exd6 e.p.). It is also a popular motíf
in chess compositions, as you have seen in our December
28 Smyllian puzzle.
Our New Year's puzzle is: What is the shortest
game ending with an en passant capture and mate?
It is clear that both sides will be cooperating to bring about an en passant
capture with mate. On our JavaScript board below you can play through examples
of games ending on move ten, move nine and even move eight. Do you think
a shorter sequence is possible, and if so what is the least number of moves
required?
1.g4 1.e4 g6 2.Ba6 Bg7 3.c4 Bxb2 4.Nc3 Bxc1 5.Nd5 d6 6.Rxc1 Kd7 7.c5 Kc6 8.Qa4+ b5 9.cxb6# 1.c4 d6 2.b4 Kd7 3.g3 Kc6 4.Bg2+ Kb6 5.Qa4 a5 6.bxa5+ Ka7 7.c5 b5 8.axb6# 1...e6 2.e4 Qh4 3.d4 Ke7 4.Qd3 Kf6 5.g5+ Kg6 6.Bh3 Qg3 7.Bxe6 Qxg1+ 8.Rxg1 h5 9.e5+ f5 10.gxf6#
- Start an analysis engine:
- Try maximizing the board:
- Use the four cursor keys to replay the game. Make moves to analyse yourself.
- Press Ctrl-B to rotate the board.
- Drag the split bars between window panes.
- Download&Clip PGN/GIF/FEN/QR Codes. Share the game.
- Games viewed here will automatically be stored in your cloud clipboard (if you are logged in). Use the cloud clipboard also in ChessBase.
- Create an account to access the games cloud.
Shortest
ep-mate | - | Game ends with e.p. capture | - | | 2015 | A00 | | |
Please, wait...
Puzzle three: A logical challenge
This puzzle was given to us – to family and friends, who spent an
hour mulling over it – by John Nunn during a pre-Christmas visit this
year. In the end a few of us solved it, but not without some fairly painful
exertion of a few billion brain cells. The problem is as follows:
A hermit occupies one of six caves. Every day
he randomly switches to an adjacent cave.
Every day we search one cave. Is there a strategy to ensure we will find
him,
whatever switches he makes? How many times must we seach a cave?
To clarify: if the hermit is in cave one or six he is forced to move to
cave two or five, which are next to them. In the four other caves he has
two choices. We of course do not know in which cave he is when we start.
Our search plan should discover him whatever he does – in fact he
can even know our full search plan and still not avoid discovery.

The above is a what we used to solve the problem on the dinner table: six
little wooden cups, with a stick to indicate where the hermit was hiding.
You make a search plan, consisting of cave numbers (e.g. 1, 3, 5, 4, etc.)
and then try to find a strategy for the hermit to circumvent it. A hint:
I solved the problem by starting with three caves (2, 2 finds the hermit)
and working my way up to six. Your answer should be a series of numbers
indicating which caves you would search in which order.
I can tell you it was a very enjoyable dinner. Most enjoyable.
Bonus puzzle four
In case you cannot handle construction or logical problems we will include
a final puzzle from our 2001 Christmas puzzle week:
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In this picture you see a real child prodigy, one who started playing
chess at an unusually early age. This chess prodigy went on to become
a very strong grandmaster, one of the best in the world. Tell us who
he is.

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Send in your solutions
Please use the
feedback form at the bottom of this page to submit your solutions.
Do not forget to give your full (real) name, the town you live in and your
email address – that is if you want to participate in our Christmas
Puzzle Prize Contest. This requires that you have solved at least one of
the puzzles on this page correctly.
Two winners will be chosen at random from all eligible submissions –
we like to reward participation, not getting everything meticulously right.
A third prize winner will be selected on the basis of the nicest message
(in our opinion) that we receive. Closing date for all entries is January
21, 2015. Note that the arrival date will not influence the selection –
so take your time.
And the prizes? They will consist of the most recent ChessBase software,
with autographs of top players – at least one a World Champion or
ex. And one of the prizes will have a personal dedication and the signatures
of all the participants of the 2014
Zurich Chess Challenge – if nothing comes in the way of us getting
them. Definitely worth a shot at winning, don't you think?