Endgame study (5)

  
An endgame study from 1926 by Alexei Troitzky.

White to move and win.
   
   

Solution:




1.Qe7+ Kd3

1...Kd5?? 2.Qf7+ winning the black queen with 3.Qxa2.
1...Kf5 2.Qg5+ Ke4 3.Qf4+ Kd3 4.Qf5+ and white wins. 

2.Qxh7+ Ke2 

2...Kxd2?? 3.Qh2+ and next 4.Qxa2. 

3.Qh5+ Kd3 4.Qf5+ Ke2

4...Kc4 5.Qe6+ followed by 6.Qxa2.  

5.Qf3+ 

Black is forced to 5...Kxd2 6.Qf2+ and 7.Qxa2.