Less than a minute remained on the clock during the biggest chess match of Bodhana Sivanandan’s short career last weekend, but to her, it was practically an eternity. As Sivanandan stared at the board, with Britain’s women’s chess championship on the line, it took her all of 12 seconds to calculate the decisive move: a knight sacrifice that would result in her capturing the queen. Understanding what was about to happen, her opponent had little choice but to extend her hand and resign. The only thing more stunning than the move was the age of the person who made it.…