A while ago, I came across the position of the diagram below. It is a so-called construction task, and as such, belongs to the realm of Fairy Chess. The point of this one is that a maximum number of consecutive checks has to be given, White and Black helping each other. As in normal problems, the position has to be legal, and without promoted pieces. (Click the symbols or the moves.)
Torre i Cavallo, 1993
1.Nh2+ f1N+ 2.Rxf1+ gxf1N+ 3.Ngxf1+ Bg5+ 4.Qxg5+ Bg2+ 5.Nf3+ exf3+ 6.Kd3+ Nc5+ 7.Qxc5+ Re3+ 8.Nxe3+ c1N+ 9.Qxc1+ d1Q+ 10.Qxd1+ e1N+ 11.Qxe1+ Bf1+ 12.Nxf1+ f2+ 13.Ne3+ f1Q+ 14.Qxf1+ Qxf1+ 15.Nxf1+ Re3+ 16.Nxe3+ b1Q+ 17.Rxb1+ axb1Q+ 18.Nc2+ Nf2+ 19.Bxf2+ and a sequence of 37 consecutive checks has ended.
When I saw this, my thoughts went back 20 years, when I had made this task the subject of a prize contest in Schaakbulletin. As far as I knew then (without mentioning it), the record for this task was 28, and dated back to 1938.
Fairy Chess Review, 1938
1.c7+ N6xc7+ 2.bxc7+ Nxc7+ 3.dxc7+ Ke7+ 4.g8N+ Rxg8+ 5.hxg8N+ Qxg8+ 6.f8Q+ Qxf8+ 7.Qe8+ Qxe8+ 8.d8Q+ Qxd8+ 9.c8N+ Rxc8+ 10.bxc8N+ Qxc8+ 11.Bb8+ Bxe4+ 12.Nd5+ Bxd5+ 13.Nc6+ Bxc6+ 14.Rb7+ Bxb7+
The legendary T. R. Dawson, the great connoisseur and composer of Fairy Chess (and inventor of much of it) wrote that 28 checks would 'almost certainly never be surpassed'. One can imagine I was very proud when no less than three of my solvers broke this 40 years old world record.
C. van de Loo
1.d5+ cxd5+ 2.cxd5+ Bxd5+ 3.Rxd5+ f5+ 4.Rxf5+ d5+ 5.Rxd5+ f5+ 6.Rxf5+ d5+ 7.Rxd5+ Kf7+ 8.Be6+ Rxe6+ 9.Ne5+ Rxe5+ 10.Rxe5+ Rc4+ 11.Bd4+ N3f2+ 12.Rxf2+ Nxf2+ 13.Qxf2+ Qf5+ 14.Qxf5+ gxf5+ 15.Rxf5+ for an unbroken series of 29 checks.
A very witty mechanism, totally different from Leathem's. Van de Loo wrote: 'It is very frustrating one cannot know when to stop. Many nightly hours were necessary to prove to me that 30 was a number that was out of reach, at least for me.'
It was an interesting coincidence that another contestant, Gieske, had also hit upon this same mechanism.
1.e5+ fxe5+ 2.fxe5+ Bxe5+ 3.Rxe5+ c5+ 4.Rxc5+ e5+ 5.Rxe5+ c5+ 6.Rxc5+ e5+ 7.Rxe5+ Qc5+ 8.Bxc5+ bxc5+ 9.Rxc5+ Ke6+ 10.Bd5+ Rxd5+ 11.Nxd5+ N3e2+ 12.Rxe2+ Nxe2+ 13.Qxe2+ Bxe2+ 14.Nhf4+ Rxf4+ 15.Nxf4+ also with 29 checks.
Tie for a new world record? No, because the endgame composer Rol had managed to go no less than two steps further.
1.h8Q+ Nc3+ 2.Qxc3+ b2+ 3.Nac2+ Bxc2+ 4.Nxc2+ dxc2+ 5.Ke2+ g1N+ 6.Rhxg1+ hxg1N+ 7.Rxg1+ f1Q+ 8.Rxf1+ Qe1+ 9.Rxe1+ d1Q+ 10.Rxd1+ c1N+ 11.Qxc1+ bxc1N+ 12.Rxc1+ Bxc1+ 13.Qe5+ Rxe5+ 14.Bxe5+ Nd4+ 15.Bxd4+ Rb2+ 16.Bxb2+ and Leathem's old setup has yielded no less than three additional checks for a total of 31 consecutive checks.
Rol wrote: 'Who finds the magic number 32?'
I had to disappoint him and myself: that magic number had already been found, as I discovered while this contest was running. As much earlier as in 1956, the Englishman Roycroft had constructed this position, with a totally different setting from those of Leathem / Rol and Van de Loo / Gieske.
A. J. Roycroft
British Chess Magazine, 1956
1.b8Q+ Nd6+ 2.Qxd6+ Ne5+ 3.Qxe5+ Kxe5+ 4.Ng4+ Qxg4+ 5.f4+ Qxf4+ 6.d4+ Qxd4+ 7.cxd4+ Bxd4+ 8.Nc6+ Rxc6+ 9.Qc5+ Bxc5+ 10.f4+ Rxf4+ 11.d4+ Rxd4+ 12.Bxd4+ Bxd4+ 13.Bxc6+ b5+ 14.Raxb5+ axb5+ 15.Rxb5+ Bd5+ 16.Rxd5+ exd5+ for a series of 32 checks.
But even that had been surpassed in the meantime with a Beamon jump by a German composer.
1.g8Q+ Kf5+ 2.g4+ Qxg4+ 3.e4+ Bxe4+ 4.Bd7+ Rxd7+ 5.Nd6+ Rxd6+ 6.Qd5+ Bxd5+ 7.e4+ Qxe4+ 8.dxe4+ Bxe4+ 9.cxd6+ Nab5+ 10.Rbxb5+ c5+ 11.Rxc5+ e5+ 12.Rxe5+ fxe5+ 13.Nxe5+ Bf3+ 14.Ng4+ Nb5+ 15.Qxb5+ c5+ 16.Qxc5+ bxc5+ 17.Rxc5+ Be5+ 18.Rxe5+, meaning the record for this task stood at 35 checks for a few years already.
'Who finds the magic number of 36?' I wrote at the time.
As we saw above, is was recently set at 37 by the Italian Ponzetto, who used a few of Leathem's old ideas.
Who will find the magic number of 38?
© Tim Krabbé, 1998