Posted by: Major Dan (markj89@charter.net) on Fri May 4 05:58:12 2001

Major Dan:
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> I generally or used to agree with you and you primarily agree with Jack, but this time I do not agree with you; therefore, in reading your last post I should first say that I come as a friend and I hope that you too will think before deciding.
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> Without rehashing everything that has been said and said again, your premise that the body slightly moving forward at only a few miles per hour builds up this additional energy for the swing is illogical and unconvincing. This small movement would generate very little energy compared to the energy necessary to get a 34 ounce bat (not a whip or a towel) to 70 – 90 mph. Equally unpersuasive is comparing a whip like effect or that of a pitcher throwing a ball to the forces that are applied to the bat. There is no whip like effect in the baseball swing or a bat for that matter.
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> My question to you is: if these additional few inches of hip movement are necessary to attain an extra 10-15 percent, then why do all of the awesome homerun power hitters (Sosa, Mac, Griffey, Bonds, etc) rotate about a point and use a stationary axis or even an axis moving backwards? Name one hitter who has more power than any of these stationary axis hitters, and moves the hips forward (to rotate around the front leg) such as you suggest? Name one golfer who hits it farther than Tiger and moves the hips forward before initiating the down stroke part of the swing or during the swing?
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> Video analysis shows us that all power is derived from the body’s tremendous rotational forces, not that of the body’s slight linear forces. Review the hitters during the home derby with a keen eye and I think you agree that these hitters do not move their hips forward. For the sake of this discussion and discussing power hitters, Nomar and lightweight weight hitters of his caliber are out of the discussion, since we are referring to what mechanics generates the greatest power.
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> In the future, I hope that you rethink your examples so that we may avoid these distractions and smoke screens involving whips, chains, high jumpers, etc. and get to comparable examples such as the golf swing or other similar movements.
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> Coach Tom
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Coach Tom -
You misunderstand one very important point. I am referring to forward movement of the hips BEFORE hip rotation, not during.
If I was not clear on that point I believe it is in part due to others misinterpreting my recent posts. I do not advocate a forward hip slide during rotation. I am suggesting that the forward movement BEFORE rotation adds something to the rotation and consequently to batspeed. I do not believe that is incompatible with what Jack Mankin considers good rotational mechanics. My observations are that the vast majority of major league hitters do exactly that - take forward movement and convert it into a powerful rotational swing.

The whiplike motion I refer to is the kinetic chain. If half the body weight of a 200 lb hitter travels at 3 MPH, even for a few inches, he is creating momentum (mass X velocity = 300). A 32 oz bat (2 lbs) would be swung at 150 MPH (2 X 150) if all that momentum were converted into batspeed.
The kinetic chain works from the bottom up - legs turn hips, hips turn shoulders, shoulders turn arms, arms/hands turn bat. The body is not 100% efficient but the wave of energy travels up the body and out through the bat (measured as bat speed). Larger slower moving parts start the swing. Smaller, lighter faster moving parts (bat) finish the swing. In this way, if energy is conserved, heavier slower parts transfer energy to lighter parts that have to move faster (mass X velocity is equal). A whip works in a similar way as the slow heavy handle's movement is transferred down the ever tapering whip. As mass decreases, speed increases. A 5 MPH handle movement can create tip speeds of hundreds of MPH. A less efficient whip-like energy transfer from forward hip slide through the kinetic chain seems to translate to about 90 - 100 MPH in the best case scenario (best ML hitters).
Yes, bat speed is generated through powerful rotational forces. I am suggesting that the linear body movements that precede this are 'fuel' used to jump start this rotational activity.
Coach Tom, the lower body actions of pitchers and hitters is similar in the sense that the hips lead and linear momentum is converted to rotational/angular momentum BEFORE it travels up the body (kinetic chain) and is converted into incredible hand speed/ball speed.
I hope these smokescreens, as you perceive them, make more sense in this light.