411 REFERENCE · Wikibooks
Chess/Puzzles/Directmates/Two-move 4/Solution
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It is quite simple to show that the only move black could have made to reach this position was b7-b5. Thus, a5 can take b5 en passant.
1.a5xb6 a3
2.b7#
8 kd bl 7 pl 6 pl nl 5 kl 4 3 pd 2 1 40