I think a few comments regarding the post of Eugene J Bleecker II are in order. First, only a very few of the instructional clips we show are from Home Run Derbies. The vast majority is the mechanics the batters exhibited in actual game situations. Second, this site has never advocated "Swinging for the fences." We do promote the mechanics that maximizes the batters potential to "hit the ball hard." If the batter makes contact above the ball's center it should produces a sizzling grounder -- meet it square and you have a frozen rope to the gaps -- and yes, if the ball is lofted, the bat should transfer enough energy to clear the fence.
Mr. Bleecker states the following: "Swinging down to the ball making contact with the middle to bottom third and then extending up through the baseball after contact, provides for the MAXIMUM amount of backspin and lift off of the bat on line drives." -- On his site, he adds, "Down to it and Up through it."
I would suggest to Mr. Bleecker that before continuing to teach this concept to his students, he first study the results from "Bat/ball Collision" tests conducted by a number of bat manufactures. Bat/Ball Collision Study
is a link to one of the studies to get him started.
These tests conclude the following:
(1) During the Bat/Ball Collision, the ball is in contact with the bat for less than 1/2000th second.
(2) The bat transverses about 5/8 of an inch while in contact with the ball.
(3) Any force applied at the handle of the bat during (or after) collision has no impact on the ball's exit speed.
Therefore, Mr Bleecker's contention that much of the ball's exit speed is derived from the batter's extension "through the ball" after contact is false. Even video analysis shows that the batter's extension of the arms (and bat) occurs after the ball is well on its way.
Then, consider his "Down to it and Up through it" cue. If the bat's trajectory is angling downward at contact, there is no way the bat's leveling out angling upward during the follow-through can have any effect on the ball's exit angle. -- In a following post, I will explain why a bat on an up-slope at contact imparts more energy to ball than a bat angling downward or even level in the contact zone.