The way the ball moves

I've always wondered while watching baseball on TV how the announcers can determine whether a pitch is a curve, slider, sinker, cutter, etc.   Now, I can tell the difference between a fastball, change-up, or straight curve, but the other ones are more subtle.   So finally being frustrated by this, I figured that the Web was wide enough to have a guide to recognizing pitches.  And I was right.   So here's my public service in the sports department:

Baseball pitches illustrated