Hmm, these smart guys missed a bit of information that we know from Al's research (found in the Tutorials and Guides section of this forum).

Briefly:
1) Younger players have a higher TEF than older players (training efficiency factor, the ratio of skill gained to condition lost). The exact rate and range is under investigation.

2) TEF decreases as stars increase. That is, the more stars, the more condition to achieve the next star.

3) More stars = marginally less condition loss for that player in a match.

#themoreyouknow