mate in 60

here's an interesting puzzle from 1952:

More like mate in 52 in 1960.

Originally posted by ilywrin
here's an interesting puzzle from 1952:
[fen]8/4p3/2p5/2p1p2K/3n3p/pP2N1pr/rb1N2p1/k1n3Rb[/fen]

Thanks for posting this one, ilywrin. It was a lot of fun.

Black is in zugzwang. Nd4 is stuck defending against Nc2#, and ...Bc3 Rxc1+ Kb2 Rb1 is mate. He will shuffle his h-Rook as long as he can, and spend his pawn tempos as slowly as possible to delay mate.

To stop the Rook shuffling, White needs to play Kg4 after Black plays ...Rh2. The timing is not right for an immediate Kg4, so White must find a way to lose a tempo. The wK is the only piece that can do it (R moves allow g1Q and the escape of Bh1). He must largely avoid dark squares to avoid a check by Black's Nd4, followed by ...Bd4, after which Rxc1+ Kb2 Rb1+ Kc3 escapes the mating net.

1.Kg6 Rh2 2.Kf7 Rh3 3.Kg8 Rh2 4.Kh8!

White triangulates, using the closest safe dark square.

4...Rh3 5.Kh7 Rh2 6.Kg6 Rh3 7.Kh5 Rh2 8.Kg4 e4!

Best. h8 is no longer safe for the wK, thanks to a discovered check from Bb2. wK is forced to take a longer route.

9.Kh5 Rh3 10.Kg6 Rh2 11.Kf7 Rh3 12.Ke8 Rh2 13.Kd7 Rh3 14.Kc8 Rh2 15.Kb8 Rh3 16.Kb7 Rh2 17.Kc8 Rh3 18.Kd7 Rh2 19.Ke8 Rh3 20.Kf7 Rh2 21.Kg6 Rh3 22.Kh5 Rh2 23.Kg4 c4!

Again, best. This tacks on another 2 moves to wK's route. Not 23...e6? which allows wK to f8 safely.

24.bxc4 c5 25.Kh5 Rh3 26.Kg6 Rh2 27.Kf7 Rh3 28.Ke8 Rh2 29.Kd7 Rh3 30.Kc8 Rh2 31.Kb7 Rh3 32.Ka6 Rh2 33.Kb6!

Remarkably, this is the only safe dark square left for wK. Black's centralized B and N are quite powerful.

33...Rh3 34.Kb7 Rh2 35.Kc8 Rh3 36.Kd7 Rh2 37.Ke8 Rh3 38.Kf7 Rh2 39.Kg6 Rh3 40.Kh5 Rh2 41.Kg4 e6

Black plays this only because he no longer has anything better.

42.Kh5 Rh3 43.Kg6 Rh2 44.Kf7 Rh3 45.Kf8!

Taking full advantage of Black's 41st.

45...Rh2 46.Kg8 Rh3 47.Kf7 Rh2 48.Kg6 Rh3 49.Kh5 Rh2 50.Kg4 e5 51.Kh5 Rh3 52.Kg6 Rh2 53.Kf7 Rh3 54.Kf6!

Now that the B/N battery is out of commission, this square is safe.

55...Rh2 55.Kg6 Rh3 56.Kh5 Rh2 57.Kg4

Black is all out of tricks, and it's time for spite sacrifices.

57...Rh3 58.Kxh3 Bc3 59.Rxc1+ Kb2 60.Rb1#

A great problem featuring accurate pawn play by Black and 5 tempo-loss trips by wK to five different dark squares.

Yes, that's what I thought was interesting about it that each time there was only one safe dark square on the entire board, and it was different each time. The problem was composed by A.Kremer and K.Fabel, published in Fairy chess review in 1952.

Originally posted by ilywrin
Yes, that's what I thought was interesting about it that each time there was only one safe dark square on the entire board, and it was different each time. The problem was composed by A.Kremer and K.Fabel, published in Fairy chess review in 1952.

Well, it's not quite true that there is only one safe dark square each time (some are chosen because they're faster, like h8 and f6), but that does not detract from Fabel and Kraemer's achievement.