Is PBCOR the Best Metric?
The graph shows data from a typical PBCOR determination. A Franklin X40 ball is shot toward a Pickleball Apes Pulse V paddle at 50 mph. The rebound velocity (Vre) and resultant PBCOR value at different locations on a Pickleball Apes Pulse V paddle face is recorded.
Two things to note:
- The maximum ball rebound velocity (Vre) of about 12.5 mph is found up toward the paddle throat at about 7" from the tip.
- The maximum PBCOR value of about 0.38 is obtained at an impact point about 3" from the tip of the paddle. The rebound velocity (Vre) at that point is only about 8.5 mph.
This seems counterintuitive. Why would the maximum PBCOR value occur at a point where the rebound velocity is at a minimum?
As can be inferred from the graph, the PBCOR value iis only an indirect measure of ball velocity; the formula assigns more "weight" to rebound velocities near the tip of the paddle by assigning a higher PBCOR values. Why? The answer has to do with the difference between the laboratory test where the paddle is stationary and on-court play where the paddle is in motion.
When a player swings the paddle, it [supposedly] pivots around a point about 2" away from the butt of the handle. The paddle velocity at 8" from the pivot point (10" from the butt) is moving twice as fast as the paddle face at 4" from the pivot point. The PBCOR formula compensates for the higher paddle speeds near the tip.
How good is the PBCOR formula in predicting ball speeds? We don't really know. One would hope that 10 paddles ranked by PBCOR would have the same ranking for on-court ball speed. Unfortunately, neither agency has run an experiment where a variety of players each use 10 different paddles where balls speeds are measured with a radar gun. One would hope that on-court ball speed reliably mirrors the PBCOR ranking.
Is PBCOR the best metric to limit paddle power? It's still an open question.
Note: Baseball had the same question. Does on-field ball speed mirror the BBCOR (ball bat coefficient of restitution) ranking of bats? The answer for baseball was Yes. The question was answered in the study A Comparative Study of Baseball Bat Performance Alan M. Nathan et al
