>>>So I'm new to this sight, I saw some of Jacks videos on YouTube and I had some questions.
In my understanding of THT, it makes no sense to me that the top arm rotates to accelerate the bat rearward, isn't that just an inert movement created by the hands beginning to slot, and the bat moving into the proper swing plane? Please explain this to me! It seems like too much emphasis is being contributed to movements that are not acting, but being acted upon! The only way for the bat to flatten out is for the bat head to move backward from the hands, otherwise you would have to swing with a completely vertical bat. I believe THT is not an action, but a reaction!
Someone please convince me otherwise; convert me!<<<
During the 1980s, I taped numerous games played in the old AstroDome. Some of the swings in those games were shot from directly over the batter's head. I collected over a hundred of these swings on a single tape. A frame-by-frame study of the bat's trajectory from this overhead view greatly increased my understanding of high level swing mechanics.
I noted that from launch (body rotation initiated) to contact, the bat arced through about 210 degrees. The first 120 degrees of the bat's trajectory was rearward toward the catcher (lag position) and then forward 90 degrees to contact. My most enlightening observation was that the top performing hitters generated much greater rearward velocity than the average performer.
The swing mechanics of the top performers continues to generate bat speed from initiation all the way around to contact -- their bat already has great velocity passing through the lag position (bat pointing toward the catcher). Average hitters advance the hands but the bat-head just slides over behind the hands with far less velocity in the lag position. - A batter with a more static bat at the lag position can not generate great bat speed in just the last 90 degrees - To generate maximum bat speed, the bat must be accelerated through the entire 210 degrees.
Slapper, if I read your post correctly, you contend a batter does not apply forces to accelerate the bat rearward -- that movement just naturally occurs as the elbow slots and the bat lowers to the swing plane. If that were true, then all batters that slot their elbow and bring the bat to the swing plane would generate the same rearward velocity.
My study from an overhead view of the swing shows there is a great difference in the rearward velocity of the top hitters as compared to the average hitter. -- I am placing below 3 videos on this topic
In the video below, note the difference in rearward acceleration of good hitters as the elbow lowers as compared to average hitters.
THT -- Good & Poor
Below is an overhead view of the swing plane and the forces that produce it.
THT -- Overhead View
I think this THT video is the one you are referring to.