[Retros] 6 e8=R#

Noam Elkies elkies at math.harvard.edu
Sun Dec 17 14:03:19 EST 2006

Andrew Buchanan writes:

> It turns out that in *5* cases, our homespun results can be improved upon:

(NB even these "homespun" results are computer-assisted by Natch or Popeye...)

> Piece Line Ours Actual

> [...]

> R e 13 11

> [...]

Pin-mates to the rescue:

1 e4 d6(d5) 2 Qg4 Bf5 3 exf5 Qd7 4 f6 Kd8 5 fxe7+ Kc8 6 e8=R#

(both versions C+ Popeye in under a second).

Mario -- you didn't specify whether "realizable" means in a sound
proof game or in an unrestricted game, but now I see it must have been
the former because g7-g8Q(R)# can be easily shown in 11 ply without
the soundness condition, e.g. 1 g4 g6 2 g6 Nh6 3 gxh6 Bg7 4 hxg7 h5
5 random Rh7 6 g8R#. Did you keep track of how many sound proof games
each minimally "realizable" promotion mate had?

--Noam D. Elkies

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