Use the measurements from the Buzzball sticks (which I use by the way) and play with those for a while. In time you will be able to judge if you need to adjust the length of the sticks (or not).
Note: you HAVE to know how your figures run in order to successfully use the sticks AND you have to learn how to tweak your bases to get your players to run how you want them to run. Even then you will find little things can occur that will be the difference between a complete or incomplete pass. You can have a receiver pointed in the correct position to hit the ball/marker but if he is on a hot spot on the field he can easily jump off course.
All in all you will enjoy using the sticks.
Don