Primacy, what does this mean?

Hello.
Perhaps it is a stupid question, but what does Primacy mean ,at the ratings in the game?

thanks for answer.

it alters how often that player is used to score when being controlled by the CPU

Thanks, by the way is this an important rating?

im guessing it has no effect on sim games because i have had players rated 90 primacy that took only 4 shots while someone with a much less primacy shot alot.

It is a significant rating as it basically determines who will be scoring the most points.