1.e4
Nc6
2.Nf3
e5
3.Bb5
f5
4.exf5?!
Accepting the gambit pawn is exactly what black wants. Black can look forward to one or more of 3 things happening: he will recapture on f5 with the c8 bishop gaining a tempo, or the deflection of white's e pawn allows black more control of the center, or black can use the half open f file to generate an attack. All 3 occured in the game!
4...e4
5.Ng1
[5.Qe2
Qe7
6.Bxc6
dxc6
7.Nd4
Nf6
8.Nc3
Qe5=
]
5...Nf6
[5...Qg5!?
6.g4
Nf6
Perhaps this idea gives black more active attacking chances than the game move.]
6.Ne2
d5
7.0-0
Bxf5
8.Nd4
Bd7
9.Nxc6
bxc6
10.Ba4
Bd6
11.Nc3
0-0
Warning bells should be going off for white, since black has all his pieces aimed at the white king.
12.d3
Bxh2+!!
13.Kxh2
Ng4+
14.Kg3
[14.Kh1
Qh4+
mate in two]
14...h5
15.Rh1
[15.Qe1
This white's only hope for a draw.]
15...Nxf2
16.Qxh5
Nxh1+
17.Qxh1
Qf6
18.Be3
Qe5+
19.Kh4
Rf5
[19...Rf4+!!
Black misses this simple mate in 7 although the moves played in the game were forcing as well.]
20.g4
g5+
21.Kh3
Rf3+
22.Kg2
Qg3#
0-1