As we know that we need total 15% skills to increase 1% of Overall rate. But we don’t know which player needs how much % to achieve that 15% skills. So if we get a tracker which tells us that the player is close to achieve the Overall %, than we can focus on that player more to increase his Overall rating.

Eg. There are two players for training A and B, A is on 3/15 that me he needs more 12% skills to increase overall rating, where as B is 13/15 that means he needs only 2% to increase overall rating, so we know that we need to focus on B more.