[Retros] Programs for Solving Retro Problems

Mario Richter mri_two at t-online.de
Sun Aug 24 15:55:27 EDT 2008

Mark Tilford wrote:

> Does it also run into trouble with detecting an un-en passant?

No, with respect to 'un-en passant', 'Retractor' works correctly,
e.g. for

(XX) problem 21-22 03/1954
a b c d e f g h
+---+---+---+---+---+---+---+---+
8 | R | . | B | . | | B | | R | 8
+---+---+---+---+---+---+---+---+
7 | . | K | . |*k | . | | . | | 7
+---+---+---+---+---+---+---+---+
6 | | . | | P | | . | | . | 6
+---+---+---+---+---+---+---+---+
5 | Q | | . | | . | | . | Q | 5
+---+---+---+---+---+---+---+---+
4 | | . | | . | | Q | | . | 4
+---+---+---+---+---+---+---+---+
3 | B | | . | | . | | . | | 3
+---+---+---+---+---+---+---+---+
2 | B | . | | . | | . | | . | 2
+---+---+---+---+---+---+---+---+
1 | B | B | . | | . | | N | N | 1 (15+1)
+---+---+---+---+---+---+---+---+
a b c d e f g h

R1B2B1R/1K1k4/3P4/Q6Q/5Q2/B7/B7/BB4NN
Last 12 single moves?
w: Ra8 Bc8 Bf8 Rh8 Kb7 Pd6 Qa5 Qh5 Qf4 Ba3 Ba2 Ba1 Bb1 Ng1 Nh1
b: Kd7

or

Gianni Donati
R0003 StrateGems Vol.1 01-03/1998
For Emily

a b c d e f g h
+---+---+---+---+---+---+---+---+
8 | | . | | . | | . | | . | 8
+---+---+---+---+---+---+---+---+
7 |*p |*q |*k |*p |*p | | . | | 7
+---+---+---+---+---+---+---+---+
6 |*p | . | | . | | . | | . | 6
+---+---+---+---+---+---+---+---+
5 |*p |*n | K |*b |*r | | . | | 5
+---+---+---+---+---+---+---+---+
4 |*r | . | | . | | . | | . | 4
+---+---+---+---+---+---+---+---+
3 |*b |*p |*p |*p |*n | | . | | 3
+---+---+---+---+---+---+---+---+
2 | | . | | . | | . | | . | 2
+---+---+---+---+---+---+---+---+
1 | . | | . | | . | | . | | 1 (1+16)
+---+---+---+---+---+---+---+---+
a b c d e f g h

8/pqkpp3/p7/pnKbr3/r7/bpppn3/8/8
Last 6 single moves?
w: Kc5
b: Pa7 Qb7 Kc7 Pd7 Pe7 Pa6 Pa5 Nb5 Bd5 Re5 Ra4 Ba3 Pb3 Pc3 Pd3 Ne3

the correct answers are given immediately, solving time 0.0 sec -
can you solve this problems as fast as 'Retractor'? :-)

Regards,

mario