Now I prefer this more economical initial position of Study 93a. The main line and the two tries all feature different systematic movements!
1st try: 1.f8Q? Ra7+ 2.Kb8 Rab7+! 2...Rhb7+? 3.Kc8 Rc7+ 4.Kd8 Rd7+ 5.Ke8 Re7+ 6.Qxe7+– 3.Kc8 Rbc7+ 4.Kd8 Rcd7+ 5.Ke8 Rde7+ 6.Qxe7 Rxh8+ 7.Kd7 h2 8.Qf7+ Kb1 9.Qb3+ Kc1= 9...Ka1? 10.Qc3++–
2nd try: 1.Qxg7? Rxg7 2.f8Q h2! 3.Qxf3
3...Rg8+!! Paradoxically, black lets the white king to escape from the eight rank! The immediate 3...Rg1? loses because of a Queen staircase on the a and b-files from b3 to b8! 4.Qb3+ Ka1 5.Qa3+ Kb1 6.Qb4+ Ka1 7.Qa5+ Kb1 8.Qb6+ Ka1 9.Qa7+ Kb1 10.Qb8++– 4.Kb7 Rg1! Another check would be fatal: 4...Rg7+? 5.Kc8!! Back to the 8th rank! (5.Kc6? Rg1 6.Qb3+ Ka1 7.Qa3+ Kb1 8.Qb4+ Ka1 9.Qa5+ Kb1 10.Qb6+ Kc1!=) 5...Rg8+ 6.Kd7!+– 5.Qb3+ Ka1 6.Qa3+ Kb1 7.Qb4+ Ka1(2) 8.Qa5+ Kb1 9.Qb6+ Ka1(2) 10.Qa7+ Kb1(2)=Main: 1.Qxh7! Rxh7
Watch this study on a dynamic board! Click here!