Softcaps:

0.5 Talent = 11
1 Talent = 12
1.5 Talent = 13
2 Talent = 14
2.5 Talent = 15
3 Talent = 16
3.5 Talent = 17
4 Talent = 18
4.5 Talent = 19
5 Talent = 20

Hardcaps:

If a player is at his maximum then he has 1 in 3 chance to gain a point/level.
If a player is at his maximum + 1 then he has 1 in 5 chance to gain a point/level.
If a player is at his maximum + 2 then he has 1 in 10 chance to gain a point/level.
If a player is at his maximum + 3 then he has 1 in 20 chance to gain a point/level.

Physicals excluded, they're random.