^I don't think it counts as intelligence. More like Experience and ... uh instincts? He did admit that he's not one of those who plan and thinks in the team. His one of the brawns in the group.
@sazny: you want Negi to become another "Ash"? NOOOOOO!!!! T^T (wait he never won a single tournament? I stopped watching it a loooong time ago so I never did know how many tournaments he joined.) I want to see Negi kick ass. Well not fate's ass but that Assassin's will be good enough. ^^