A rather nasty surprise greeted Black when White played his next move (his 14th). Upon receiving the move in the mail, Black promptly resigned. What was the move, and why did Black resigne? (See Diagram)
From Dyckhoff-Prewonitz, Correspondence, 1929: 14.d5! and Black Resigned because if 14…exd5 15.cxd5 Na5 16.Ng6+! fxg6 17.h3 and the queen is trapped!