Uber - I got the following from
http://www.fastpitching.com/index.html
I think these average speeds are pretty accurate for the midwest, but I would put heavy emphasis on the
extremely rare top speed numbers. For example, a 13u consistently throwing 61 will be known by every D-I college coach east of the Miss. Extremely rare.
I'm assuming you want to work on timing for hitting. Using these average speeds, just fire up an Excel spreadsheet and do a time-speed-distance calc. and you'll be on your way. For a change up, I always used a speed that is roughly 78% - 80% the speed of the fastball. That's typically what you'll see from a good back-hand change with lots of back-spin.
10U - Avg. Speed 38-42 - Top Speed 48-53 Low to mid 50's is very rare.
12U - Avg. Speed 44-50 - Top Speed 53-59 Upper 50's is extremely rare but we have seen as high as 61 mph from a 13 year who was still eligible to play 12U
14U - Avg. Speed 49-54 Top Speed 56-61
16U - Avg. Speed 53-57 Top Speed 60-68 Again high 60's is very rare but there are a few capable
18U - See 16U