Chasing a Halladay Changeup

Roy Halladay of the Philadelphia Phillies starts Tuesday's All-Star game for the National League.  There is no pitcher in 2011 better at getting batters to swing out of the zone at a change up:

Pitcher	Team	Change Ups	Chas%
Roy Halladay	PHI	339	0.573
Felix Hernandez	SEA	482	0.486
Carl Pavano	MIN	370	0.481
James Shields	TB	572	0.479
Kyle Lohse	STL	337	0.468
Chris Capuano	NYM	451	0.459
Anibal Sanchez	FLA	335	0.452
Justin Verlander	DET	415	0.447
Ricky Romero	TOR	370	0.444
Dillon Gee	NYM	384	0.441
Shaun Marcum	MIL	582	0.435
Cole Hamels	PHI	430	0.434
Roy Oswalt	PHI	229	0.429
Max Scherzer	DET	381	0.426
Bronson Arroyo	CIN	228	0.416

Roy puts a large gap between himself and #2 Felix Hernandez.  Halladay achieves this by getting more sink on his change up than most right-handed pitchers:

RHP change up movement, 2011.Roy Halladay, change up movement, 2011.With the extra drop, batters go fishing down:

Roy Halladay, swing rate on change up, 2011.Even if batters make contact with these pitches, they're so low they'll probably wind up with a ground ball.  Keep your eye on Roy's change up Tuesday night, and see how many AL batters chase it.