Mike Piazza planned on giving Roger Clemens the Austin Powers karate chop the next time the two faced off.  He detailed his preparation in his autobiography.  The fued between the two began in the 2000 World Series when Clemens plunked Piazza on the noggin so Piazza took karate classes.  Seriously?

http://msn.foxsports.com/mlb/story/mike-piazza-took-karate-lessons-to-fight-roger-clemens-after-bat-throwing-incident-021013