It gets you slightly ahead of the person you're slapping. I don't know whether it actually slows 'em down or the reason they get a little behind is just because you're making 'em swerve but it's useful sometimes. --- "lol mad and in denial, Linetrix is gaurenteed to be no older than 17"-GoombaX Hypocrisy at it's finest.
It's hard to learn to use, but I've maneged to knock someone off the track (if they're close enough to the edge). It's also just the right amount to make them miss an item or boost --- I have a Ph.d in Horribleness