1.Qc3? but 1...Ke6!

1.Qe8? but 1...Kc4!

1.Sba5? but 1...Kc5!

1.Sca5? but 1...Kd4!

1.Se5? zugzwang.

1...Kd4 2.Kg4 Kd5 3.Kf5 Kd4 4.Qd2#

but 1...Ke6!

1.Qe3? (A) [ threat: 2.Sa5 threat: 3.Qe5# 2...Kd6 3.Qe7+ Kd5 4.Qe5# ]

1...Kc4 2.Sd8 (B) zz. Kb5 3.Qc3 zz. Ka4 4.Qb4# 3...Ka6(b6) 4.Qa5#

[ 2...Kd5 3.Qd4# ]

but 1...K*c6!

1.Sbd8! (B) zugzwang.

1...Kc4 2.Qe3 (A) zz. Kb5 3.Qc3 zz. Ka4 4.Qb4# 3...Ka6(b6) 4.Qa5#

[ 2...Kd5 3.Qd4# ]

1...Kd6 2.Qe5+ Kd7 3.Qe7+ Kc8 4.Qb7#

[ 1...Kc5 2.Qb4+ Kd5 3.Qd4# ]