Posted by: Jack Mankin (mrbatspeed@aol.com) on Tue Apr 27 13:59:58 2004

>>> To cast -
To throw off or away
To cause to move or send forth by throwing
To fling
To launch
To sling
To thrust

To extend-
To stretch
To lengthen
To reach outward in space
To open or straighten out, unbend
To cause to be longer
To thrust

THE LEAD ARM CASTS AND THE REAR ARM EXTENDS.

Place a ball on a tee at the front edge of the plate - dead center and then assume a normal stance (a foot position so as to have the bat's sweet spot make contact with the ball's sweet spot and to drive the ball to center field). If you could somehow manage to mark the point in space where the hands are at contact, then move the tee to the outside (in the black) edge of the plate. With your feet in the original normal position, place the bat's sweet spot on the ball's sweet spot so as to drive the ball to center field and mark this second point in space where the hands are at contact. The hands had to EXTEND from the one point to the other. Whatever method you use to get them out further ( you can EXTEND ALONG A CIRCLE, AS WELL AS EXTEND ALONG A STRAIGHT LINE), the point is that they have extended from one point to the other (REACHED OUTWARD IN SPACE) to reach the ball. And if you note the hand's position from the center plate position to the outside plate position you will see that in the outside plate position the hands are FURTHER AWAY FROM THE SWING AXIS. They are STRETCHED, LENGTHENED, CAUSED TO BE LONGER from the original position. They are extended. Also note that the rear arm has straightened (has OPENED OR STRAIGHTENED OUT), has caused the elbow to UNBEND. <<<

Hi Ray

Your definitions and description of how you see "extend" and "casting" are very helpful to my understanding of your position. With this information, I will try to point out our differences and hopefully, we can reach a conclusion that will satisfy both of us.

My definition of "casting" would agree with all your synonyms except for the last one - "To Thrust." All of your other examples imply angular movement. To me, "to thrust" an object, implies a force that propels it straight away from an axis rather than around it. I noted that you used "To thrust" as synonyms for both casting and extending. I would have it in the extending column only.

Note: I have always found it interesting that due to the linear, A to B, principles that have been taught to coaches for generations, any mechanic that produces a circular motion was believed taboo and would ruin a batter's swing. -- If the batter did not swing down at the ball, he was "looping." -- If he rotated around a stationary axis, he was "spinning." He must post the front-leg and drive his back-hip forward (back to center). -- If the batter's hands did not go straight from A to B, he was "casting." The negative connotations placed on these terms are so ingrained in our thoughts that most coaches still react negatively to them even today.

Ray, I fully agree with your definitions of "To extend." Therefore, our differences appear to be how we use these terms in the context of generating a wide hand-path for outside pitches. You stated, "The hands had to EXTEND from the one point to the other." You would be correct if the swing had only one axis of rotation (around the spine) - the wider the path of the hands, the more the hands and arms would need to extend.

However, while conducting research of the baseball swing at the U of CA (San Bernardino), we found while using their Motion Study Computer System that there are four main Axis of Rotation involved in the swing. --- (Axis 1) the Spine -- Hips and shoulders rotating around a fairly stationary axis. (Axis 2) The lead-shoulder joint - the biceps area of rotation. (Axis 3) The lead-elbow - forearm rotation. (Axis 4) Point between the wrist. All of these Axis of Rotation produce a series of accelerating arcs. And on the outside of these accelerating arcs is "The Final Arc" of the bat-head.

Ray, we found during this study that linear extension mechanics produced a good deal of forearm rotation around Axis 3. This meant the lead-elbow started bent and then straightened out as the hands were thrust outward. Whereas, we found there was little to no rotation around Axis 3 with rotational transfer mechanics. This is because the lead-elbow remains in a fairly fixed position during the swing. In other words, the lead-arm remains fairly straight during the swing regardless of pitch location.

As I just pointed out, the lead-arm does not extend for outside pitches with rotational mechanics. What allows for a wider or a tighter hand-path is the arc position of Axis 2 (lead-shoulder joint). If the lead-shoulder rotates all the way around to the 105 degree position (farthest from the plate), the lead-arm (and hands) will be drawn into a tight hand-path for pitches middle-in. For outside pitches, less shoulder rotation leaves Axis 2 closer to the plate allowing the lead-arm (and hands) to cast out into a wider arc.

In conclusion, I would say the hands do not extend for outside pitches. They are cast into a constant arc around axis 2 regardless of pitch location (except when jammed and the elbow flexes). It is the arc position of Axis 2 that determines how wide the hand-path becomes.

Ray, I have tried to answer your question with as much detail as possible. As we agreed, this is a hard topic for the written word. Therefore, I understand there may be follow-up questions. But try not to be offended if I also need questions answered.

P.S. Ray, just for my curiosity, have you discussed this topic with Paul at his site?

Jack Mankin