07/11/20 Puzzle: Solution

In this puzzle, white can checkmate in two moves.

Congratulations!

Thank you to everyone who sent in their answers. You received at least 1 point. If you correctly guessed the first move, you received 2 points. If you sent in at least one full solution you got 3 points, and you received a further point for each correct variation on the solution.  This week, the following players received 3 or more points for their solutions:

Rob (4)
Aathiran Oyalood (4)
Earl (4)
Natalie Weaver (3)

The current top 3 scorers are:

Aathiran Oyalood (8)
Earl (8)
Rob (7)

This Week’s Solution

On first considering this puzzle I looked at where the black king could travel in two moves. The white king and pawns are doing a good job of hemming the king into the corner, but I decided that if the king moved to b7 it would be impossible to checkmate him and cover both the a8 and b8 squares as I have only knights, bishops and pawns at my disposal! These pieces are only able to attack one colour square at a time.

The only way I could ever attack the b8 square in two moves would be either to play Bc1, followed by Bf4, or to play b5 followed by Bd6. Neither of these two move combinations would be a checkmate as they do not cover enough of the white squares accessible by black king. It was therefore necessary to prevent the King getting towards a8/b8 by preventing the initial move to b7.

There are two ways to prevent Kb7. Be4+, and Na5+, and one of these moves has to be the first move in the solution. After Be4+, if Kd6, c5++ is a neat pawn checkmate, or even b5++ (releasing the black squared bishop). The problem is, that instead of playing Kd6, black can play Kb6 instead. c5+ does not work here as, now the bishop has moved, there is nothing preventing the black king moving to either b5 or a6. Be4+ therefore had to be eliminated as a solution.

Na5+ must therefore be the first move of the solution. As this move is a check, the only possible moves are again by the black king as no blocks or captures are available. In fact, the two options for the king are the same. Kd6 or Kb6. After Kd6, all the squares around the black king are attacked, so all that is required is an unblockable check, and to make sure we do not lose control of any of the squares in the king’s field.

There are two ways to check the king here – similar to the solutions above. After c5+ now though, we lose control of d5 which was previously guarded by the c pawn. In the above solution it worked as the bishop on e4 had covered that square. The other check does work however. b5++ is checkmate, opening the line of the black squared bishop.

If Kb6 instead, we not only need a check, but we also require an attack on the king’s new escape square on a6. a6 and b6 form a straight line, and a combination of white and black squares, but don’t give up! Even without a rook or a queen we can still cover both these squares together, with the help of some tactics.

As earlier, we can open the line of one piece, by moving another. This is a great way to utilise two pieces at once, and cover unusual patterns of squares in a single move. If we play c5 we can unleash our white squared bishop which is perfectly lined up with the king’s escape square. c5++ therefore attacks the king, and the escape square and is the answer to the second variation.

It is not unusual to struggle with checkmate in twos! The visualisation skills necessary to complete these are advanced, making them much more challenging than the checkmate in one puzzles. You have to hold two pieces in different positions in your mind AND still consider a third move. Focusing on the kings field (the 8 squares surrounding the king) and keeping track of how (and if) it changes is invaluable! Also, make sure to double check your solution with move/capture/block.

If you struggled, you can make it easier by setting up the position on a board and moving the pieces around, but remember that in a real game you cannot get away with this behaviour! It is important to build your visualisation skill up so you can better see through your plans on the chess board. If you would like to practice your visualisation skills further I would recommend studying Sharpen your Skills or Visi-Power.

What To Do Next

Tomorrow you will be able find next week’s puzzle on our blog (the first puzzle in the new block). The puzzler with the highest score at the end of the block will win a free chess lesson with the teacher of their choice and a solver badge and spot/two solver spots. Our runners up will receive a solver badge or a solver spot if they already have a badge. Consistently sending in your results is key to winning so make sure you subscribe below to get notified about the checkmate puzzles the moment they are published.


Diagram courtesy of www.chess.com


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