when Mr Know-It-All really does know it all

Truly smart men are a different kettle of fish altogether. they are very self-knowledgeable, and are acutely aware of the famed male ego and its pitafalls.... . they recognise the dangers of letting their pride rule rational thought and are actively on the lookout for any attempts to stroke their ego.... you cannot bend such men through flattery, and manipulative techniques only last for a while. the only voice these men listen to is the voice of reason.....
it's not easy to win against such a man.. in fact, you shouldn't even try to. the only way to beat him is to let him win without even trying. stop trying to force your point for a while and instead deny him the challenge of an intellectual conflict, thereby denying him the satisfaction of trumping you.
it is important to get away from the specific argument and address the struggle for control. for him, the hidden agenda is always: i'll prove i'm right and make you give in:
what strategy we want to use against him for "mr know-it-alls, for once in their lives, usually have no idea what to say"