Can some one explain this???

[Toxcatl]

As far as I know in associations all see the player's quality like the manager of the team see it . So this manager has this player with 79% general quality .
I'm I missing something here?

Do you know about relative and absolute quality?
1% is not actually 1%, it's -55% shown as 1%. You can't calculate the average relative quality because of that, you need to do it with absolute quality and then convert it back to relative.
Kto has pretty much answered it.