Those of you who read TCS ('The Cambridge Student', a student newspaper) may have noticed the fairly recent addition of a chess problem each week, supplied by CUCC. Our intention was that the solution would be provided in the same edition as the problem, but this week the solution was not published. So, we have reproduced the problem here, with solution, for those of you who can't wait to see the solution or verify the answer.

White to play and checkmate in three moves

At first sight this looks easy, but have you taken into account Black's clever defensive try? If you want to see the solution, it is given below in white text - to see it, click and drag to highlight it.

This was a composed position. White starts with 1)b7. Now 1)...Bxg4 succumbs to 2)b8(Q)+ Bc8 3)Qxc8 mate.

A better try for Black is 1)...Bg8. White must avoid 2)b8(Q), drawing by stalemate. Instead, he underpromotes to a Bishop: 2)b8(B)! Black’s Bishop can now move, after which 3)Be5 is mate.