Some people thought the wolves smell the sweat of the pitcher's (MC) mitt or the ball itself. No, they actually smell the catcher's (Krusche) mitt to sense its location, and thus predict the path the ball would take to reach the mitt.
Krusche actually mentioned a way to counter it (only raising the mitt at the last possible moment to catch) but MC discouraged it since she isn't fast & skilled enough to do so yet. Of course, there's always the "drench yourself in foul stuffs to mess up their hyper sense of smell" method but I doubt they'll ever resort to that.