1.Qb4? Sd6!; 1.- Qe1+? Qg3! 2. Bf2 hxg4

 

1. Qe4! threat 2. g5+ Kg3 3. gxh6x

(1. - Qg1 2. gxh5+ Kxh5 3. Rxh6x)

1. - Sd6 2. Qe7+ Kg3 3. gxh5x

1. - Qd6 2. Bf2+ Qg3 3. g5x

1. - Qg3 2.  g5+ Qg4 3. Bf2x

 

Alternating moves by scheme:                                         

a1-b1/a2-b1; c1-a1/c1-a2 and 3 model mates