He is the expert on "real potential"
.
And a final word of advice: Don't overvalue real potential. It's not everything. I've seen guys with true pot of almost perfect 100 need 7 seasons to even be decent and guys without high pot being stars for years already. Plus, the factor of luck is unpredictable. Great pot can not improve as much as low pot can improve despite.
Furthermore, knowing true pot of a player does tell you little, you would have to see it in relation to the rest of the league, to his time in the league (experience, which will drop it by 5-10 each year) and his overall ratings already achieved (so having a rating of "A" already and true pot of 98 will in most cases mean you WON'T improve to A+. Just my experience ...)