chess online

rickypr18

Probably because of
2. Nd4+ Kb2
3. Nb5! winning either pawn or bishop and hence winning the game

Therefore black cant play Kb2 and have to play Kc4, but after Nc2 black cant win pawn race. Blacks apparently have some chances to draw in this endgame with bishop for 3 pawns, but whites are better anyway and have decent chance to win - black king is too far from pawn and they can't exchange the queens

no.. i think black will move 2. ... Kb4 in response of the suggested move (Nd4)

reason behind Bc7 being wrong is that only the correct move can stop Knight from capturing black's pawn (or in other case, giving white a queen as in continuation).. see white will sacrifice it's Knight for the black pawn which is the only way black can win.. continuation with 1. ... Bc7 would be
1. Nc6 Bc7
2. Nd4+ Kc4
3. Nc2 a2
4. g4 Kb3
5. Na1+ Kb2
6. g5 Kxa1
7. g6 Kb2
8. g7 a1=Q
9. g8=Q