[Retros] More double check mates in 5.5 (Re: New entries!)

[Noam Elkies]

> double checks:

> Qd1/Ng1     SPG in 5,5 - RS 6/96


Actually 5/96 according to my records: his message of May 26, 1996
contains the line "Double check (4.5) [that is, 5.5 --NDE]:
1.e3 d6 2.Qh5 Bh3 3.Nxh3 g5 4.Nxg5 Nf6 5.Nxf7 Nd7 6.Nxd6#."

It can also be done with tempo loss:
1 Nf3 Nc6 2 Ne5 Nd4 3 N:d7 N:e2 4 Q:e2 h6! 5 Qb5 h5 6 Nf6# (C+, 1 sec.)

Likewise Bf1/Ng1, e.g.,
1 Nf3 b6! 2 Ne5 Bb7 3 N:d7 B:g2 4 B:g2 b5 5 Bc6 b4 6 Nf6## (C+, 600 msec.)

Some more double-check mates: Ra1(h1)/Bf1 with
1 a4(h4) d5 2 Ra(h)3 Bg4 3 Rc3 B:e2 4 Rc6 Ba6 5 Bb5 e5 6 Re6##
(C+ in 300-400 msec. each).

and, with some more effort, Ra1(h1)/Qd1:
1 a4(h4) d5 2 Ra(h)3 Bf5 3 Rc3 B:c2 4 Rc6 B:a4 5 Q:a4 e5 6 Re6##
(C+ in 14 and 8 seconds respectively).

NDE