How Does Weight Effect the Numbers?


So let's get to training and where or if weighted balls fit in.

One of the researchers/instructors in the field has come up with an expectation conversion chart (our term, not his). His information says that if a pitcher can throw a 5 oz ball at 90 mph, then the same effort will move a 7oz ball at 78 mph and a 10 oz ball at 65 mph.

Ball Weight Velocity
with same effort
Speed
Differential
(mph)
%
Drop
5 oz 90 mph - 0%
7 oz 78 mph -12 13% 
10 oz 65 mph -13 28%

Another high-level instructor who focuses more on pitcher conditioning uses greater weights... 7, 14 and 21 oz or more. His experience shows a 5-1/2 to 6 mph drop each time the weight goes up by one of those increments.

Ball Weight Speed
Differential
(mph)
Velocity
(calculated)
%
Drop
5 oz - 90 mph (assumed) 0%
7 oz -6 84 mph 7%
14 oz -6 78 mph 13% 
21 oz -6 72 mph 20%

And a third instructor who is a former Major League pitcher and pitching coordinator quotes a 2-3 mph drop between weights when the changes is just 1 oz, for instance 4 oz, 5 oz, 6 oz and 7 oz baseballs.

Ball Weight Speed
Differential
(mph)
Velocity
(calculated)
%
Drop
4 oz 0 90 mph
(assumed)
0%
5 oz 2-3 mph 87-88 mph 3% 
6 oz 2-3 mph 84-86 mph 6%
7 oz 2-3 mph 81-84 mph 9.5% 

To help you decode all this, we have not only charted their numbers but added calculated columns in an effort to get apples to apples, sort of. The % drops are not always consistent, in fact depending on which guru you accept, the loss in velocity is from 3% per extra ounce, to as much as 6% per ounce.

 

The important - in fact critical - point in all this is that you cannot expect to throw a heavier baseball as fast as a regulation weight without a significant increase in the physical effort required. So the mere act of working with weighted balls, requires you to recruit the body's muscles and sequence the momentum transfer much more efficiently, more fluidly, and more intently. So you had better be fully warmed up - sweating even - and have very good mechanics BEFORE you start to push the velocity with weights beyond the sliding scales shown here.

And that, of course, is the bottom line in our view. If the readings on the radar gun show only the relative % drop we show here, then you may be throwing a weighted ball, but not with any more training effort and therefore not with any purpose or performance improvement.