Black to play and win (medium)
 ← 
 → 
1...Ng4 2.hxg4 Qe3+ 3.Kh2 Rh8!! 4.Bf3 hxg4+ 5.Kg3 Qf4+ 6.Kf2 g3+ 7.Kg1 Rh1+ { 7...Rh1+ 8.Kxh1 Qh4+ 9.Kg1 Qh2# } 0-1
[Event "?"]
[Site "Buenos Aires"]
[Date "1972.??.??"]
[Round "?"]
[White "Kasas"]
[Black "Debarnot"]
[Result "0-1"]
[FEN "4r3/5pk1/2Q2n2/3B2pp/2b2q2/P6P/6P1/R2R2K1 b - - 0 1"]
[SetUp "1"]

1...Ng4 2.hxg4 Qe3+ 3.Kh2 Rh8!! 4.Bf3 hxg4+ 5.Kg3 Qf4+ 6.Kf2 g3+ 7.Kg1 Rh1+
{ 7...Rh1+ 8.Kxh1 Qh4+ 9.Kg1 Qh2# } 0-1