IBM Ponder This #233 · September 2017

This month's challenge was suggested to us by Merse E. Gáspár from Hungary (thanks!)

Fischer Random Chess (also known as Chess960; see https://en.wikipedia.org/wiki/Chess960) is a version of chess designed by Bobby Fischer, the former world chess champion, in 1996. It uses the standard chess board and pieces, but it randomizes the starting positions of the pieces on the first home rank. Just as in standard chess, the white pawns are placed on the second rank, while all the remaining white pieces are placed randomly on the first rank, with two restrictions:1. The bishops must occupy squares of opposite colors. 2. The king must occupy a square between the two rooks. Black's pieces are placed equal-and-opposite to White's pieces.

Fool's Mate (see https://en.wikipedia.org/wiki/Fool's_mate), which is also called "Two-Move Checkmate", refers to checkmate achieved in the fewest possible number of moves from the start of the game. In standard chess, Fool's Mate can only be achieved by Black on move 2 with the queen. The rare checkmate is so named because it only take place if White is playing extraordinarily poorly.

Problem: How many of the 960 different Fischer variations mentioned above have the possibility of allowing a kind of Fool's Mate, or the shortest possible checkmate carried out by Black in just two steps?

Solution

Best opened after a real attempt

To be added.