I found my ability to perform well at certain board games (even those previously unknown to me) to improve after spending some effort studying chess. I attribute this to the improved ability to analyse abstract positions, to construct an increased number of possible moves and opponents' responses in my head in a short amount of time. Though confirmation bias etc.

As far as that is true, it's because all RTS or FPS games are essentially the same. I say this as a once avid chess player and gamer.