I think it's a bit more than that. You can study your opponent within the context of the game, and you can study your opponent outside the context of the game, and these might yield different strategies. If you're a chess player and you study your opponent's past games to concoct your strategy, that's one thing. If you're a chess player and you pull up your opponent's medical records to find that they are epileptic, and then you deliberately induce a seizure in them during the game in order to force them to forfeit, that would be a quite different thing. IOW, there's a difference between attacking the player and attacking the output of the player. And the line can be fuzzy, e.g. deliberately frustrating your opponent with mindgames, in which case you will have people arguing either that the mindgames are part of the game (a metagame), or that it is unsporting to taint the purity of the game with meta concepts (where the line might be visualized as "anything that can't be fed into a chess engine").