# Problem 0506910

Problem 0506910 Tactics Analysis Board

White to play.

White is winning, but what is the quickest way?

Here I think Ncb5 is if anything stronger than Ndb5 (given as the correct answer), as in some lines it leads to win of Q or mate. Look at these variations:

After 1 Ncb5:

(a) 1 ... axb5 2 Nxb5 gives the same position as 1 Ndb5 axb5;

(b) 1 ... Qb8 2 Nxe6 fxe6 3 Nd6+ Kd8 4 Nf7+ Ke8 5 Nxh8 is no slower than 1 Ndb5 axb5;

(c) 1 ... Qb8 2 Nxe6 axb5 3 Bf4 d6 4 Bxd6 Qa7 5 Nc7+ Ke8 6 Bc5+ wins the Q;

(d) 1 ...Qb6 2 Nf5 Qa5 3 Nbd6+ Kd8 4 Nxf7+ Kc7 5 Qd6#;

(e) 1 ...Qb6 2 Nf5 Qa5 3 Nfd6+ Kd8 4 Nxf7+ Ke8 5 Nbd6#;

(f) 1 ... Qc5 2 Nxe6 forces mate or win of Q;

(g) 1 ... Qe5 2 Bf4 Qxf4 3 Nxe6 fxe6 4 Nd6+ Kd8 5 Qd4 Ng6 6 g3 Qf6 7 Qb6+ Ke7 8 Rad1

Black is now two pieces up, but his pieces are stymied and White's attack seems very promising.

Anyone see a flaw in the above analysis?