11/12/2013 added typical pitch angle to 'How Do I hit..' recommendation
2/10/2011 added physics section, clips
11/30/2010 corrected optimal hitting area from 1 inch to 1/2 inch below centerline
Should I Hit the Top of the Ball?
This is another confusing topic when discussing or instructing a baseball swing.
Some recommmend hitting the top of the baseball in order to generate topspin.
You do generate topspin when you hit the top, but you want backspin to generate lift on a line drive.
Some say you should hit the top of the ball in order to generate backspin. You can't generate backspin by hitting the top.
Don't believe us? Let's get started.
Regardless of the backspin induced, it is physically impossible for a ball hit above the centerline to attain the lift angle to even come near the fence much less clear it.
That is true for a bat angling downward or on an up-slope at contact.
hit the bottom-half of the ball, producing backspin, which is very desirable on balls hit in the air
The Hardball Times has written articles about studies of MLB hits where they analyzed the percentage of various hits that were converted to outs and I have summarized the results:
In 2008, the rough batting average for each type works out to: line drives .710, groundballs .260, outfield fly balls .170, infield flies .010
There is an optimal strategy for achieving maximum range [of a batted ball]. For a typical fastball the batter should undercut the ball by 2.65 cm [see note] and swing upward at an angle 0.1594 rad [9 degrees].
Note: 2.65 cm is approx. 1 inch. However, reader bbrages at BBF pointed out that the authors were measuring the distance from the centerline of the bat to the centerline of the ball. This point of contact is approximately 1/2 inch below the centerline of the ball.
Show Me The Physics. What Really Happens?
Here are some excerpts of high speed videos from Dr. Alan Nathan, Physics Professor, Univ of Illinois,
where they shoot a ball at a stationary bat (left) to determine the spin and direction of the ball after striking the bat.
Hit the top of the ball Dr Nathan Hitting The Top Of The Ball
Here is what happens when you hit the top of the ball
Notice the topspin.
Notice the ball going down.
Hit the bottom of the ball Dr Nathan Hitting The Bottom Of The Ball
Here is what happens when you hit the bottom of the ball
Notice the backspin.
Notice the ball going up.
If you still have doubts after this, we can't help you.
Do Not 'Hit the Top of the Ball'
Hit the ball just below the center line (approximately 1/2 inch) for maximum lift and speed on a line drive
Where To Hit The Ball
If you hit the top of the ball, it can only go down, and the ball will rotate down like a curveball.
[If you are trying to hit infield grounders, this is the way to go, because of the crazy spin.
However, if you are trying to hit line drives, hitting the top of the ball is detrimental.]
If you hit dead center of the ball, it knuckles and dies.
If you hit the middle, inside of the ball, it spins sideways and gets no lift.
If you hit just below the center line, it goes up - with backspin like a 4 seam fastball.
If you hit the ball too far under the center line, its a popup.
What difference does it make anyway?
It's Just a Blur
I understand that you can't see a ball by the time it's 7-8 feet from you.
Think about a 5 foot tall NASCAR car in turn 4, then think about it buzzing by directly in front of you. Then imagine a 3 inch ball going by.
So, you probably could not really hit the ball in any particular point on purpose. Unless...
How do I Hit the Proper Spot on the Ball?
Jason Giambi Swing Plane
h/t Baseball Fever
Match your swing plane with the plane of the pitched ball.
Linear hitters generally swing directly down and the planes look like an "X".
Many coaches and instructors incorrectly use cues like "hit the top of the ball", "swing down", etc.
Rotational hitters that take their back elbow to their hip, will get the bat head below their hands, and the path of the bat head matches the plane of the pitched ball.
The typical MLB fastball pitch angle is roughly 10 degrees downward.
So, you must swing 'up' 10 degrees simply to be even.
According to SportsScience, a typical home run swing uses a 20 degree swing path.
Sports Science - line drives (L), home runs (R)
