1.Nbd6+
Forking the king and the f7-pawn, which will lead to a
further knight fork of the two rooks!
1.Ned6+ also works: 1...Kb8 2.Nxf7 Bc5 3.Nxh8 Rxh8 the
difference is in where White's remaining knight will be. In this line it's
on b5, but in the text it is on e4. A centralized position is
better for the knight, so that's why 1.Nbd6+ is preferable to 1.Ned6+
1...Kb8
1...Bxd6 2.Nxd6+ Kc7 3.Nxf7 arrives at essentially the same
position, the difference being that Black's dark-squared bishop is gone.
If you are going to lose material, as a general rule
don't exchange any more pieces than you have to. The fewer pieces on
the board, the more powerful a material advantage is, that's why the general
rule of thumb is - when ahead in material exchange pieces, when behind
exchange pawns. So the text move is preferable because it avoids
the exchange of the bishop.
2.Nxf7
After 2...Be7 3.Nxh8 Rxh8 White finds herself an
exchange and a pawn to the good. With careful play, that ought to be
enough to win.
