Chess

Now here's a nice little problem (by Josef Halumbirek) to begin the week. It's White to play and mate in ... well, how many? All those pawns queueing up on the h-file give a strong hint of what is in store. It's going to be one of those puzzles where White repeats the same manoeuvre a number of times, forcing Black at the end of each cycle to push a pawn, then sniping off the pawns one by one. Even guessing that, however, it may come as a surprise to learn that it is White to play and mate in 130. Composed in 1955, this is the record for a problem with only one white man other than the king. Here's how it goes.

The first task is to pick off the knights: 1.Qd1+ Rc1 2.Qd3+ Rc2 (Bc2 allows Qc3) 3.Qxf1+ Rc1 4.Qd3+ Rc2 5.Qd1+ Rc1 6.Qd2! Rc2 7.Qe1+ Rc1 8.Qe4+ Rc2 9.Qxh1+ Rc1.

Now we need a spot of delicacy: 10.Qe4+ Rc2 11.Qe1+ Rc1 12.Qd2 Rc2 13.Qd1+ Rc1 14.Qd3+ Rc2 15.Qe4! The same position as at move nine, but it's Black to play. Since 15...Kc1 allows mate on e1, and 15...Bb3 loses to 16.Qe1+ Rc1 17.Qd2 Rc2 18.Qd1+ Rc1 19.Qxb3, he has to move a pawn.

So 15...h2 16.Qe1+ Rc1 17.Qd2 Rc2 18.Qd1+ Rc1 19.Qd3+ Rc2 20.Qe4 and Black must move another pawn. After 20...h1=Q 21.Qxh1+ Rc1 22.Qe4+ Rc2 23.Qd2, the white queen gets back to e4 on move 27, forcing another pawn move. Black has, in all, 15 non-promoting pawn moves (including a6), each answered by a series of five checks, and four promotions on h1, answered by seven checks. So after 123.Qe4! Black has left only a pawn on h2. The solution then ends 123...h1=Q 124.Qxh1+ Rc1 125.Qh7+! Rc2 126.Qe4 Bb3 (he has nothing else) 127.Qe1+ Rc1 128.Qd2 Rc2 129.Qd1+ Rc1 130.Qxb3 mate! Bravo.