Posted by: Chris O'Leary (chris@chrisoleary.com) on Thu Mar 1 14:00:04 2007

"the more the hips rotate while the shoulders remain fixed, the greater the 'X factor' and thus the more powerful the shoulder rotation. This would mean that the hips should be approaching open before the shoulders rotate. This may be true for the golf swing. However, my study of a hundred or so over-head views of MLB swings did not support this theory for the baseball swing."

This is also the case when it comes to baseball pitchers. On average the differential is around 45 degrees and in some cases you will see a differential approaching 90 degrees. For example here's Casey Fossum...

http://www.chrisoleary.com/projects/Baseball/Pitching/Images/Examples/Example_HipsRotatingBeforeShoulders_CaseyFossum_001.jpg

However, I agree that you do not see this degree of separation in ML hitters. While the hips do turn ahead of the shoulders, the differentil is more like 10 to 20 degrees.

Jack, do you have a sense of why you see this difference? Does the length and barrel-loading of the bat allow guys to get away with a different movement pattern.