Reply to "The average pitching speed at age X is this!"

I would suggest that the PG class percentiles are not the "best of the best".  Class of 2017 is showing a best of 95 (outier) with an average of only 78.  That would imply that there are lots of 2017's throwing slower than 78 - but can also be the result of some prior year's speeds being pulled forward.  There can be a pretty wide age range in these classes (upwards of 24 months from youngest to oldest), but PG does help demonstrate the pretty side range.  You can look up individuals and start to get an idea where the 70th, 80th, etc. percentiles sit.  I'm not saying the 50% of 2017's throwing slower than 78 are highly successful (many of these may have stopped pitching altogether years ago but still have old speeds tracked) but they do represent some very average players who happen to throw at PG events.  There may be some data set elsewhere that may be better - and the data you can readily access off of the PG site is limited, but if you poke around enough on PG, including looking up individual players and scanning tournament pitching speeds, you do start to get a feel for a class' speed on the high end and low end.  I always figured something around 75% percentile meant you were hanging in there from a speed standpoint.  Looks like 82 (both RHP and LHP) appears to be the 75% for current 2017's.