Ran across this player today who had a ridiculous amount of improvement over four seasons.  Wondering if anyone has ever topped this.

http://whatifsports.com/hd/PlayerProfile/RatingsHistory.aspx?tid=12368&pid=2983521

Overall? No. In positional cores, my man Scott Hendricks, starting ratings and caps

ATH: 39 to 66
SPD: 56 to 99
DEF: 35 to 80
PER: 26 to 99
BH: 43 to 71
P: 47 to 82

Similar improvement in DEF/PER/P, slightly less in ATH/BH, significantly more in SPD. So I would say that for his position, he improved more. But he didn't improve in REB/SB/LP/ST, so overall, not even close. 

This guy improved 310 pts over the 4 years and was my first guy ever drafted.  Granted he started significantly higher and had a redshirt year, but 300pts is a great imrpovement, 376 is crazy

I have a guy that is a Jr at 739 and started at 465 no redshirt. He has 6 black categories and one blue still. Charles Evans from Aurora Should be around 300 Improvement buy EOY.

I did 378 and 370 at DII . The 370 is still going but all red.

I recruited for a friend a long time ago, and the gem of the class was Jeffery Perry.  Started at 32/1/83/30/75/39/1/1/1/49/48/21 for a 381 overall.  Not sure what the final rating was, but it was over 700, and he finished with over 2400 points and 1200 rebounds for a team that made the F4 in both of his upperclassman years.

whatifsports.com/hd/PlayerHistory/Stats.aspx