There is a correlation to distance thrown to pitching velocity, but it varies due to wind, temperature, altitude, humidity and individual. One of the benefits to long tossing is that it gives you a way to measure your performance each time you go out. All you need is a field and a bucket of balls or a partner. I can’t actually think of a more effective way to get better at throwing a baseball than…D’Oh…throwing a baseball. Low finish is correct in that you can be the best long tosser in the world and the worst pitcher, but my experience is that the best long tossers typically are the best pitchers.