When you play a CTTP game, your scorecard will show your hole score in green with a white box (personal best) or without (current score only).
The system records these for your 'potential best' score. I do believe, as I have posted elsewhere, that tibbets actually has a 'potential best' of 0.0 at Kiawah because he has aced every single hole... not at the same time, mind you, but all rounds totalled.
So generally if you see the white box, it is your best ever... (unless it's on the first hole, as stated above, sometimes that one glitches.)