It is interesting that Turing worked with some of the best British chess players among them Golombek and Alexander. I am not sure how to characterize it, but he is considered a creative genius at a level and was certainly very important and successful in the code-breaking efforts during WW2.
He would play with Golombek, who I think could allow Turing to change color at a point of his choosing during the game. Although, I am not sure of the constraints; maybe it was up to a certain move. Golombek could then beat Turing from Turing's presumably losing position. I have never played at those odds, but I can't imagine, assuming that Golombek was playing to win, that Turing had much of a position, to begin with. On the other hand, perhaps, Golombek would try to keep a more or less even game so that he had chances. Anyway, I really wonder how weak of a player Turing was and if perhaps some of his games survive.