White wins

Opposite-coloured bishops, pawns on both sides poised to queen. But White strikes first, with just enough activity to force a sudden and decisive finish.

1.Ba7+ Ke4 2.Bd4!

2.b8=Q? a1=Q yields nothing of note — and after 3.Qb4+? d4, the tables even turn in Black’s favour. White must therefore part with the bishop, first drawing the enemy king onto a more compromising square.

2...Kxd4 3.b8=Q a1=Q

Though both sides promote, it is now White who dictates the action, engineering a flawless tactical sequence that ends with a decisive skewer.

Note that 3...Kc3 is of no avail. One illustrative line runs: 4.Qc7+ Kb2 5.Kd2 a1=Q 6.Qb6+ Ka3 7.Qa5+ Kb2 8.Qb4+ Ka2 9.Kc2, and White is clearly winning.

4.Qb4+ Kxe5 5.Qe7+ Kf4

5... Be6 6. Qg7+ +-

6.Qh4+ Ke5 7.Qh8+ Kf4 8.Qxa1 1-0

A quiet bishop sacrifice, a precise sequence, and finally, the fall of Black’s queen. The arc is complete!