*BOB*on*Bush*: Agreed, the problem is different with games of incomplete information like Battleboats. Nevertheless, in those games the best strategy is certainly not to play each game in the same way. It is rather the most boring strategy.

The problems I have with private games :
1) They are often used by the strongest players, so that nobody can learn from seeing their games. I have nothing personal against those who do that, after all it is allowed by the system and gives them an advantage. But in my opinion BK is scoring an autogoal by allowing that.

2) They can be used to hide cheating, either cheating by use of playing computers, either by pre-arranged games designed to manipulate the rating system. The second option would not be valid if private games were always unrated as have been proposed, but the first one remains.
Of course Fencer can still see the private games, but when cheating occurs it is always the users who spot it in the first place.

Well, if private games were limited to unrated games of incomplete information (Battleboats, Dark Chess, ....) it would already be a good start.