The numbers I posted were curve fits based on averages. With the data I had available at the time the two ends of the range were absolutely useless and an artifice of the curve fit I selected. I don't for a moment believe that a pitcher is done gaining velocity at 17yo. I do believe that on average they don't gain a whole lot of velocity after 17 yo.
Curve fits just give us trends and they can't account for late maturers, people who develop their coordination late, recovering from injuries, people who learn their mechanics late, etc.
I never took the effort to build a database from PG's results which would be much better. I believe "bum" did do something like that and got slightly different, but generally similar results. I'd recommend searching for his results. He titled the thread "average velocity increases" and posted it in early September, '06.
The data I got from asking was surprisingly realistic although on the high side, but one would expect that from a more "elite" group such as HSBBweb and other sources that I drew from. The important part was the differences between the reported speeds due to height and age and not the actual speeds. I did make adjustments in reported speeds to match them up with cruising speeds. The average cruising speed from the database/curve fit for an elite 6' tall, 16yo was around 81 or 82 mph on a Jugs gun, or about 80 mph on a Stalker. I also threw out one or two outliers such as Robert Stock. Overall I don't think the results were that unrealistic. While he was healthy my son tended to run right along the curves as he grew, although his max velocity was equal to the "elite" cruising velocity. Unfortunately, we haven't been able to gun him for over a year and he's grown about 5" during that time meaning that according to those curves he would have picked up about 8 mph in velocity. He probably won't be able to throw full speed again for another 6 months or so and who knows where things will go from there. Just another data point but I've got 5 15yo sophmore pitchers who all cruise around mid to high 70s and max out from 79 to 81 on a JUGS gun. They range from about 5'9" to 6'1" and I believe the 5'9" one throws the hardest.
Sorry, micdsguy but I did spend a lot of time on some very limited data. It was just a fun exercise for me and I tried to make sure that I didn't over sell the value of the information.
PG,
Your memory must be faulty, I don't remember coming out on top too often when we debated.