Posted by: Jack Mankin (MrBatspeed@aol.com) on Sat Dec 7 09:42:17 2002

>>> I appreciate your insight. Question for you. In the Final Arc 1 video, your student knocks over the bag by rotating around the chair. If I threw the bat in the exact same spot at the same speed, you would say that bag would fall over still? I find it hard to believe, but will consider it. I have much to learn about leverage. If Mark McGwire and David Eckstien swung the same bat, with same batspeed, there balls would go the same distance? Sorry I don't clearly understand. <<<

Hi Coach

You asked ; “In the Final Arc 1 video, your student knocks over the bag by rotating around the chair. If I threw the bat in the exact same spot at the same speed, you would say that bag would fall over still?” – Many years ago I hung a heavy bag in our garage. I thought that how far the bag would swing after contact would be a good indicator of the power in my sons swing. But the more they worked at making the bag swing, the poorer they performed at the plate.

I have since learned that what makes the bag swing requires a very different type of swing than is needed in hitting a baseball. In fact, I discovered that the better the baseball swing, the less the bag should swing. So when Brian knocked the bag over in “The Final Arc 1” it indicated to me that his mechanics and timing needed some work.

Below is something I wrote earlier that that may explain the different type of mechanics needed to “swing the bag” as compared to hitting a ball hard.

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The following will clarify the use of the heavy bag as a practice tool and clear up some of the confusion some coaches have. The goal of practicing with a heavy bag is not to drive the bat through the bag or cause the bag to move or swing and this should not be taught. In fact, practicing with the heavy bag has wrongly been equated to that of hitting deflated basketballs or similar objects. The principles behind practicing heavy bag drills are very different than mechanics developed from hitting deflated basketballs. The problem stems from a misunderstanding of what occurs at contact and the follow-thorough portion of the swing.

The concepts surrounding the "follow-through" phase of the swing have long been misunderstood. In the past, coaches were taught to hit the ball hard by teaching batters to continue driving through the ball after contact. Thus, it is understandable why many coaches would adopt drills that would require the batter to continue "pushing" the bat through the follow-through phase, such as hitting deflated balls.

For example, to propel a deflated basketball forward requires the basketball to remain in contact with the bat for an extended period of time. The bat would stay in contact with the deflated ball for eight or more inches after the initial contact. Therefore, swinging at deflated basketballs would definitely require the batter to continue applying energy to the bat after making contact, but this is not true for hitting a baseball or softball.

Studies have shown that the baseball is only in contact with the bat for approximately 1/2000 of a second. During this split second, the bat moves forward less than 3/4 of an inch (while in contact with the ball). Therefore, any energy applied to the bat after contact has no effect on the ball's flight. In fact, it is simply wasted energy. A batter with good transfer mechanics will deplete all energy for generating bat speed prior to or by contact.

On the other hand, the weaker hitter will develop considerable bat speed after the bat has passed through the optimum contact zone. In this case, the bat-head is dragging as it enters the contact zone and in order to accelerate the bat-head to maximum velocity, the average hitter continues to apply forces to the bat well after passing the optimum contact point, much like hitting a deflate ball. This is also the reason why weaker hitters have little power to the opposite field and most of their better-hit balls are pulled foul.

>>> If Mark McGwire and David Eckstien swung the same bat, with same batspeed, there balls would go the same distance? Sorry I don't clearly understand.<<<

Coach, like you, I would have thought that the batter’s weight would effect the ball’s flight. But data from scientific test prove otherwise. You will have to decide what you wish to believe.

Jack Mankin