Estudio de Alexei Troitzky (1912). Blancas juegan y ganan.

1.a8=C+!! [ 1.f8=D Cb6+ 2.Re5 Cd7+ 3.Rf4 Cxf8 4.a8=D Ce6+ 5.Rg3 Dd3+ 6.Df3 Dd6+ 7.Rh4 Dd8+ 8.Cf6 Dd4+; 1.a8=D? Cb6+ 2.Rd4 Dd6+] 1...Rd7 [ 1...Rc8 2.f8=D+ Rd7 3.Cf6+; 1...Rb8 2.f8=D+ Ra7 3.Cc6+] 2.f8=C+!! [ 2.f8=D? Dd3+ 3.Rc5 Da3+] 2...Rc8 3.Cxg6 Ce3+ 4.Cxe3! [ 4.Re4? Cxg4 5.Rf3 Ce3 6.Rg3 Cd5! 7.Rxh3 Rb8] 4...h2 5.Cb6+ Rc7 6.Rc5 h1=D 7.Ced5+ Rd8 [ 7...Rb8 8.Cge7 Dg1+ 9.Rb5 Db1+ ( 9...Df1+ 10.Cbc4 De2 11.Ra6 Ra8 12.Cc7+ Rb8 13.Cb5) 10.Ra6 Dd3+ 11.Cbc4] 8.Cc6+ Re8 9.Cce5 Dc1+ 10.Cbc4 Dg1+ 11.Rc6 Dc1 12.Rc7 1–0