"Damn," he said, but he didn't seem too concerned. "Ah well, it was worth a shot anyway."
Still, her comment about having a photographic memory made him feel hopeful rather than worried, as it made her sound like Hermione - who, in spite of her great memory and tendency to excel at everything, always seemed to fail when playing chess with him. It was the reason why he liked playing with her, really, as he felt it did her some good not to be the best at something.
"That puts me at a disadvantage, then, because even if I had a photographic memory I couldn't remember my future plays. Again, ah well." He was still grinning as he said this, though. As he made his next move he was already working on an entirely new strategy focusing not only on possible moves but on his opponent's possible strategy. Rose was both like him and Hermione, and he'd have to be prepared for what either of them would do in her place. Or for any of Harry's other mind-boggling tricks, of course, since she probably knew them too.