Insights from The Physics of Baseball

I've referred to this book in several posts, particulary here but have never done much of a review. I came across some insights that I recorded after reading the first edition of the book when it was initially published. I thought they might be interesting for some.

A bat has 2 vibrational nodes (points where there is no vibration when struck by a ball), one near the handle and one near the end. That's why it stings more when you hit the ball midway between the two nodes (usually about 5 to 27 inches on a 35" bat) than right on the handle (it has nothing to do with it being closer to your hands except that it just so happens that the first vibrational node is under your hands).

Aluminum is stronger than wood and has higher elasticity (it compressses about 1/10 as much as the ball whereas the wooden bat compresses only about 1/50 as much as the ball, thereby transferring more energy to the ball). A 380 foot drive with an wood bat may go as much as 415 feet with an aluminum bat. An aluminum bat stings less because it vibrates less.

The impact lasts about 1/1000 of a second. Therefore a tight or lose grip makes virtually no difference, nor does releasing the top hand after impact. The impact happens so quickly that the signal does not get processed until long after the ball is gone.

A 10 degree upward swing ideal.

For maximum distance the ball should be hit upward at a 35 degree angle.

Corking a bat provides no advantage that cannot be produced by legally doctoring a bat (honing the barrel, choking up, cutting length off the barrel). The primary thing it does is lighten the bat. The rubber balls or cork put in the barrel are only good for muffling the hollow sound that will be produced. The elasticity of these items is less efficient than the wood that it replaced.

A well hit ball produces a sound an octave higher than middle C.

Mickey Mantle's 565 foot drive off of Chuck Stobbs probably only went 510-520 feet. Anybody would be hard pressed to hit a ball more than 545 feet in a normal conditions off of a major league fastball.

A rising fastball does not rise. It simply sinks less than the normal ball (about 2.5 ft as opposed to 3 feet).

A curve ball that seems to break 14.4" actually only varies from the straight line made by the hand to the final location by 3.4".

Old time players didn't wear batting gloves as much possibly because the hickory bats they used did not sting their hands nearly as much (hickory has more of the properties of aluminum). Heavier bats do hit the ball farther.

Moving from a 2.5" barrel of most wodd bats to a 2.75" barrel of an aluminum bat only increases the effective hitting surface by 4%.

The drag coefficient of a baseball decreases dramatically between 50 and 120 mph unlike that of a smooth ball. A smooth ball cannot be hit or thrown nearly as hard or far as a baseball at baseball velocities. This might indicate that a pitcher by strengthening his arm may be able to gain more additional velocity than you might imagine. This is why a four seam fastball may add up to 2 mph on a fastball (the four seam ball is rougher and reduces the drag). A sinking fastball can be thrown by gripping leather only, producing less spin, little upward Magnus force causing it to drop faster (possibly 4 to 6 inches). Magnus force is produced when one side of the ball is rotating faster than the other, reducing pressure on the slower side, making the ball curve.

A scuffed ball will curve towards the scuffing since the scuff will produce turbulance on that side of the ball i.e. less drag while the other side has more force on it, pushing it to the scuffed side.