How's this Velocity?

My 13 year old son threw 71 mph with a sore arm and no mound, so can anybody give me an estimate of what he could throw if he fully rests his arm and was on a 9"-1ft mound

Could be more, could be less. A lot actually depends on his mechanics – and how similar they are to “nonmound” throwing in this instance.

71 is super pitching velocity for a 13 yo, by the way. My guess is that he might be able to throw a few mph harder off a mound. Maybe 2 or 3 mph??

I guess the question is, why was he throwing for velocity with a sore arm?

my son throws almost every day

Is this because you believe throwing nearly every day will strenghten his arm?

How often does he throw with a sore and tired arm?

im going to have to agree with the other guys, you shouldnt have your son throw when his arm is sore and tired…especially when hes trying to go all out…

no offense this sounds bad… and if its you incouraging him to throw everyday well you need to step up to the plate and tell him thats the wrong thing to do a sore arm is a sign especially if hes throwing just to see how much velocity he can generate