Posted by: rql () on Sat Apr 5 08:43:41 2008

> >>> I agree it is difficult to extract the value out of Nyman's very confused info.
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> However, I think that his simulations can be useful as long as you do not buy into his faulty interpretations as discussed in this prior thread where his previous modelling (intended to discredit Jack) actually supported Jack's descriptions. <<<
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> Hi Tom
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> An added note: As it relates to the baseball swing, Nyman’s “ball on a string simulation” is flawed from the outset. Note that the gravity factor acting on the ball is set greater than tension pull on the string from the rotating arm. These settings result in the ball falling faster from gravity than the rotating arm’s displacement rate (note the slack attained in the string). This linear acceleration (vertical falling) of mass does not occur in the angular trajectory of a ridged bat.
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> Nyman’s simulated settings completely distort the trajectories obtained from “swinging of a ball on a string” with the correct angular displacement rate of the hand-path. I also took note that his simulation induces the straightening of flexed lead-elbow during rotation. This produces a far less efficient CHP for generating bat speed than obtained from maintaining a constant lead-elbow angle.
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> Jack Mankin

>>A few years ago some may recall where I did a test with a lead arm swing vs a rear arm swing and then both arm swing.there was a 280 foot hit on a tee with just the lead arm,the 2 arm swing went about 310 in the air,so about 10% difference.at 1st you could say there is little help by torque but 10% relly helps.Next I believe that there is some torque being applied by the pull of the bottom part of the hand from rotation and the push pressure on the bat where the thumb wraps around the bat on top of hand,yes some torque applied by only 1 hand,maybe it is rotation helping the bottom and the wrist forcing forward to stay straight so no bat drag.However this is a long swing takes time to build rotational energy and tough to control bat.The tht and the top hand I feel help create control but also the quickness necessary to get a swing to catch up to 90mph pitch,that top hand helps get it through the zone quickly but not with all the great batspeed increase you may think the top hand delivers.My analysis is bottom hand is rotation and batspeed but slow to build,top hand creates more torque for bat quickness and control,you must have both to create the great swing,torque and rotation.