The following video made the rounds in the baseball blogosphere on Friday. It compares the way Charlie Morton of the Pittsburgh Pirates and Roy Halladay of the Philadelphia Phillies throw the two-seam fastball.
Morton worked on copying Halladay's delivery during the off-season. His pitching stats certainly have improved.
The two seam fastball is supposed to sink. In 2010, it didn't sink all the time:
In 2011, Morton puts more of the density below the X-axis:
That more closely matches what Roy Halladay throws:
There is one big difference that remains between the two, however. Roy works both sides of the plate with his fastball, Morton works middle-in to righties, middle-out to lefites. He doesn't throw to the catcher's right hand:
Morton gets the same movement as Halladay, but can throw it to multiple locations yet. That may be the lesson for next winter.