@spaceysmile

In the line A) after 12.Kd6 also Qb6+ is an option for blacks which is more direct than 12.Nb7+ that involves the complex and fascinating 13.Qxb7+! deflection on the d8 square. After 12. ... Qb6+ 13.Ke5; c1Q blacks look ok because the d8 square is guarded by queen b6 and the whites king is not safe.

Well, I remembered the game of Fisher's though I was unsure whether I could be able to calculate it. I should note that it took my half hour to realize it is Fisher's game.

About the second one, I think the point is as following:

1.Qh2+ Ka8 2.Qg2+ Kb8 3.Qg3+ Ka8 4.Qf3+ Kb8 5.Qf4+ Ka8 6.Be4+ Nxe4 7.Qxe4+ Kb8 8.Qe5+ and

a)8...Ka8 9.Qd5+ Kb8 10.fxe7 b1Q+ 11.Kc5 Qb5+ 12.Kd6 Nb7+ 13.Ke5 and this position is still complex for me , cannot see a decisive win yet, though I also couldnt see any other better variation.

b) 8...Bd6 9.Qxd6+ Ka8 10.Kc7 a1Q 11.Qd5+ Ka7 12.Qc5+ Ka8 13.e7 +- so that is not an option for black.