Posted by: Jack Mankin (MrBatspeed@aol.com) on Fri Apr 4 11:53:43 2008

>>> I agree it is difficult to extract the value out of Nyman's very confused info.

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. <<<

Hi Tom

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.

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.

Jack Mankin