Chess Problems: Solutions to Half-pin Problems
By David Friedgood
Last time
I discussed the Half-pin Theme and set a couple of examples for solving. Today’s
article gives the solutions with comments.
[Event "L'Italia Scacchistica"] [Site "?"] [Date "1919.??.??"] [Round "?"] [White
"Antonio Bottacchi"] [Black "Mate in 2"] [Result "*"] [Annotator "Friedgood,David"]
[SetUp "1"] [FEN "B3N1K1/1n1p2B1/2r5/3k4/Q2N4/5P2/8/2b5 w - - 0 1"] [PlyCount
"3"] [EventDate "1919.??.??"] {The methodical way of solving this problem would
begin by noting that there is a flight square on c5, and that if it were Black's
move then 1...Kc5 has a mate already set by 2.Qb5#. This is what the composer
would like you to see, as it delays your finding the key move, which changes
this set-up quite radically. On the other hand, an experienced solver, seeing
that the d4 knight is laterally adjacent to the black king, would know that
it is very likely to be the key piece. The main reason for this is that, by
moving, the knight could land on a square from which it could deliver mate.
And indeed the key is } 1. Ne6 $1 {giving up control of e6, but in exchange
gaining control of c5 and threatening 2.Qe4#. Note that the threat still works
after 1...Kxe6, partly because of the clever use of the white king to guard
f7. Now the half-pinned pieces on b7 and c6 do their stuff, each making two
variations by moving to protect e4: 1...} Rxe6 {(Continued as main line)} ({In
the four thematic variations a half-pinned piece self-blocks and leaves its
partner fully pinned:} 1... Rc4 2. Qxd7#) (1... Nd6 2. N8c7#) (1... Nc5 2. N6c7#)
({ The only non-thematic variation is also a self-block:} 1... dxe6 2. Qd4#)
2. Qb5# {This lightweight problem shows symmetrical play, not only in the geometrical
sense but also in the thematic motifs in the variations.} *
[Event "Time and Tide"] [Site "?"] [Date "1952.??.??"] [Round "?"] [White "Comins
Mansfield"] [Black "Mate in 2"] [Result "*"] [SetUp "1"] [FEN "2B1Q2K/8/5pp1/2N2P2/Rr2pk2/6R1/1r3p1B/4q3
w - - 0 1"] [PlyCount "3"] [EventDate "1952.??.??"] {For this problem, your
solving can be aided by your knowledge of problem themes. The half-pin on the
fourth rank is easily spotted, but is a little puzzling, as if the b4 rook moves
upwards or 1...e3 is played, the same mate 2. Nd3# is possible. Also, the existence
of the bishop/rook battery is odd, as there is no way it can produce a mate
with the king on f4, given that the rook is tied down to covering four potential
flight squares. However, if the white queen moves away, then 1...Ke5 would lead
to 2.Rd3#. Clearly, the queen is going to make the key and it takes just a small
imaginative leap to come up with the beautiful} 1. Qb5 $1 {This "ambushes" the
queen behind the knight so as to threaten 2.Ne6# discovering protection of e5
and f5. The mate after} Ke5 {is in place (continued in main line)} ({The only
two other defences are the thematic half-pin moves} 1... Rxb5 {allowing} 2.
Nd3# {as already noticed in the set play}) (1... e3 {on the other hand cannot
now be met by 2.Nd3 as there would be no protection of the e4 square. Instead
there is a lovely pin-mate by} 2. Qb8#) 2. Rd3# {The half-pin here forms the
core of the problem, but the key move, giving up a flight and offering the queen
is the star turn.} *
There will be more about the half-pin theme in my next article. Any queries
or constructive comments can be addressed to the author at david.friedgood@gmail.com.
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.
