Below are tables showing the performance that can be expected from high school, college, and professional major league pitchers. A great difference exists in the spin rates created by poor vs. exceptional breaking ball pitchers.
BASEBALL A good breaking ball at the college or pro level requires at least 35 RPS. Some pitchers achieve more than 40 RPS consistently on their curveballs or sliders. In high school, the best breaking balls are typically around 35 RPS. There is more variability in the spin rate on fastballs, depending on the type of fastball thrown and whether the pitcher is capable of putting movement on the pitch.
The best pro pitchers like Justin Verlander throw a curveball at 45 to 50 RPS. An article by Tom Verducci about the spin rate of pitches in Major League Baseball (see at Verducci - Sports Illustrated) indicates the following advantage for high spin curveballs:
The MLB data above shows that a curveball with very high spin is twice as likely to result in a strike than one with low spin and 50% more likely to result in a strike than a curveball with average spin. Very high spin versus low spin results in a 32% decrease in batter hitting average and a 47% decrease in batter slugging percentage (total bases/at-bats).
SOFTBALL A good breaking ball (curveball, riseball, dropball, or screwball) requires at least 19 RPS. Some pitchers achieve more than 22 RPS consistently with their breaking balls. A few are known to throw riseballs consistently at 30 RPS. In high school the best breaking balls pitchers typically throw around 23 RPS. There is more variability in the spin rate on fastballs, depending on the type of fastball thrown and whether the pitcher is trying to put movement on the pitch. Although the spin rates for fastpitch softball are slower than for baseball, the effect of spin is more pronounced than with baseballs because of the larger surface area and higher seams of a softball.
*High School data from National Fastpitch Coaches Association (NFCA) recruiting camps.
GENERAL GUIDELINE FOR JUNIOR & SENIOR YEAR HIGH SCHOOL PITCHERS*: SPIN RATE (RPS) 17.0 - 18.9 Average 19.0 - 21.9 Good 22.0 and more Excellent
*This guideline is for high school pitchers without RevFire based training.
BREAKING BALL SPIN RATE GUIDELINE FOR DIVISION I COLLEGE FASTPITCH SOFTBALL: SPIN RATE (RPS) 20.0 - 21.9 Average 22.0 - 24.9 Good 25.0 and up Excellent