im 5 4 110 and would like to know the maximum velocity i could gain in one year :?:
I’m not sure what you are trying to say. How old are you?
You should focus on your change-up and hitting corners first. Being 13 I don’t suggest you to get on any kind of intense workout. Long toss will help but you should be focusing on mechanics and location first.
Some speed will come with maturity some you need to work on yourself but being your age I find no need to pressure you to go and workout just to gain speed.