This is a game I had just a few minutes ago. When I ran it through Fritz, imagine my surprise.
White had recaptured the pawn on c4 with 22. dxc4. What should Black play?
22.... Nxb4 looks nice. Winning a pawn and gaining a tempo due to the discovered attack on White's queen.
Can you find a better plan?
Be warned, the calculation of the correct line is not easy as there are 2 important variations you have to consider that runs up till 6 ply deep. Remember tactics predominate nearly everything in chess.
Now what if I were to tell you there is a way to win at least a piece?
That got your interest hasn't it?
If you need to, stop now before looking at the answer below:
Ready? The winning move.
The White Queen is forced to move and there are 2 important variations:
Let's take a) 23. Qd1 or any other Queen move except 23. Qe3 - I'll explain later
Now comes the shocker 23....e5!!
a1) If the bishop moves away say 24. Bd2, then 24... Qh3 is decisive threatening mate on g2.
25. f3 (forced) Qxg3+
26. Kh1 Nxf3 and Black's attack crashes through and White must give up material to stave off mate.
a2) If the bishop takes with 24. Bxe5 then 24... Nf3+
25. Kg2 Nxe5+ wins the bishop
Now we go back to the other continuation
b) 23. Qe3 now e5 doesn't work but....
23... g5!! is a killer
Obviously the pawn cannot be taken as 24. hxg5 hxg5 with mate on Rh1#
24. Bxg5 is no solution because of Knight fork after 24.... hxg5 with 25... Nf3+ to follow.
That just leaves
24. Be5 Nf3+
25. Kg2 Nxe5+ winning the bishop
For all purposes, there is a stronger move in the earlier variation but given the practicalities of play, winning the bishop is fairly decisive.