George Duke wrote on Fri, Jul 24, 2009 12:11 AM UTC:
[Try the Smullyan retrograde 19.July] Congratulations to Joe Joyce for Jack of Spades 23.July. The other one 23.July close try.
But here's the deal:
8 __ __ __ __ __ __ __ On b3 as Joyce experiments, how could King be
7 __ __ __ __ __ __ __ in double check by the last move of Black? In
6 __ __ __ __ __ __ __ two words, IM-POSSIBLE, except one way.
5 __BR_ __ __ __ __ __ [Retrograde analysis of which T. R. Dawson has
4 WB bp_ __ __ __ __ __ thousands in heyday of modest CVs 1910-1950]
3 __WK_ __ __ _BB__ __ What must have happened is ...Bishop -d5 check.
2 __ _wp__ __ __ __ __ 2. Pawn c2-c4; Pawn b4xc3 (en passant) double
1 __ __ _BK__ __ __ __ check (!) 3. King b3xc3...
a b c d e f g h So King should be put back on c3, and Black's
move now. If King goes to -a3 in Joyce's scenario, we would still have to be seeing the black pawn on c3. So he must have taken on c3. [Maybe White knocked it off on purpose thinking the only way he is going to win is on time.]
[Try the Smullyan retrograde 19.July] Congratulations to Joe Joyce for Jack of Spades 23.July. The other one 23.July close try. But here's the deal: 8 __ __ __ __ __ __ __ On b3 as Joyce experiments, how could King be 7 __ __ __ __ __ __ __ in double check by the last move of Black? In 6 __ __ __ __ __ __ __ two words, IM-POSSIBLE, except one way. 5 __BR_ __ __ __ __ __ [Retrograde analysis of which T. R. Dawson has 4 WB bp_ __ __ __ __ __ thousands in heyday of modest CVs 1910-1950] 3 __WK_ __ __ _BB__ __ What must have happened is ...Bishop -d5 check. 2 __ _wp__ __ __ __ __ 2. Pawn c2-c4; Pawn b4xc3 (en passant) double 1 __ __ _BK__ __ __ __ check (!) 3. King b3xc3... a b c d e f g h So King should be put back on c3, and Black's move now. If King goes to -a3 in Joyce's scenario, we would still have to be seeing the black pawn on c3. So he must have taken on c3. [Maybe White knocked it off on purpose thinking the only way he is going to win is on time.]