Game1:
1. e4 e5 2. Bc4 Bc5 3.Qf3 Nh6? (defending the weak f7 square. However Nf6! is much better.) 4. d4! exd4 5.Bxh6 gxh6?? 6. Qxf7#
Game 2:
1. e4 c5 2. Nf3 Nc6 3.d4 cxd4 4.Nxd4 e5 5.Nf5 Nge7?? (correct is d6) 6. Nd6#
Game 3:
1. f4 e5 2. fxe5 d6 3.exd6 Bxd6 4. Nc3?? (much better is Nf3!) Qh4+ 5. g3 Qxg3+ 6. hxg3 Bxg3#