When people describe what makes one pitcher more effective than another, they usually discuss velocity or various aspects of finesse (command, off-speed, pitches that move a lot, etc.). However, I have seen quite a few cases of players with similar velocity and finesse levels where one is much more effective than another at game time. What are the other factors that makes some pitchers harder to hit than others?
To keep the answers a little more focused, I'll provide examples of kids I observe on my son's 12u summer team. We are an average AA team in the SF Bay area. We get destroyed by AAA teams but we generally have competitive games against other AA teams.
I bought a radar gun last month and have gunned around 20 different pitchers from many different teams. 12u AA calibur pitchers around here are low to high 50s for the most part though there is typically 1 or 2 outliers per team in terms of velocity. I consider an outlier 12u pitcher one who throws above 60 MPH or below 50 MPH.
Here's what I observe among our various pitchers, in height order, who I will label with letters. Height is my visual estimate, while velocity is something I got from my pocket pro radar gun:
A: 5' 7" tall, thin, 65 MPH max velocity. Sidearm delivery. On a good day can throw a knuckle curve for strikes but usually just relies on velocity. Is in the beginning stages of acquiring good command. Has 3rd best results in terms of WHIP and ERA on the team. Usually gets very good results vs AA teams but AAA teams easily hit his 65 MPH fastball and his only chance against them is when he is having a good day with both his command and knuckle curve.
B: 5' 6" tall, big upper body, probably heaviest guy on the team at maybe 140 lbs. 57 MPH max velocity, does not use legs and lower body very well - surprising how hard he throws give what he's (not) doing with his lower body. Does nothing but throw hard strikes. 2nd best results on our team. Against most AA teams, the top half of the order gets a couple hits and the bottom half does nothing each time through the lineup. This is they guy I am most curious about - why is he so effective with nothing but 57 MPH fastballs?
C: 5' 3" tall, lean, athletic, shortstop type of body, 57 MPH Max. His mechanics are a little rough but he mostly throws strikes. Sometimes has good days, sometimes bad days, #5 pitcher on the team in terms of results.
D: 5' 1" tall, very athletic shortstop type of body, 58 MPH max. Nice looking mechanics. Despite having second highest velocity on the team, it's like batting practice most times he takes the mound. Lots of quality hits, occasional errors, very few walks as he has a good strike %. Has worst WHIP on the team because of all the hits. This is another one I'm very curious about - why with velocity so similar to B does this guy get hit so much while the other guy does not? Neither one does much with off speed or command.
E: 4' 11" tall, very skinny, less experienced ball player. 48 MPH and has a changeup he can throw for strikes that's about 43-44 MPH. Huge arc to the pitches coming in. He gets given very little pitching time. Strikes out very few batters. But mostly he gets great results because hits are weak grounders, weak popups, and gigantic fly balls for the most part - though occasionally does give up hits. He had few enough innings that his results are statistically insignificant but if I included him in the rankings he would have the best WHIP and the best ERA.
F: 4' 9" tall, 84 lbs thin, 55 MPH fastball. This is my son, and the finesse pitcher on the team. He has unusually good command and a variation of a football curve he invented which comes in much slower and moves a lot (it's called a crosser because he crosses his index and middle finger). He gets the best results on the team, and is the only pitcher on the team who has much of a chance against a AAA team (though still not too much of a chance).
I know why F is good - even decent 12u batters struggle against good pitch sequencing where speed and location keeps changing. So I don't need that one explained.
I know why E is good. Though coaches rarely trust their slower throwers, it turns out that most hitters are simply not used to pitches coming in on a big arc so they're not lining up the bat angle right, and their timing is off (many foul balls) with the slow speed. And this guy even has an even slower speed! Our coaches are coming around to realize they should use this guy more.
I know why A is good. He's got the highest velocity on the team and a nasty off-speed pitch when he's able to throw it for a strike.
But what about B, C, and D? They all have very similar velocity. None of them has an off-speed pitch they throw with confidence. Yet B is by far the most effective. D is an average pitcher. While C is batting practice?
What are those other factors besides velocity and finesse?