Is there a rough formula for how much each extra point of OBP and SLG is worth over X plate appearances? Obviously it’s not going to be perfect or precise ideally you’d use baseruns or linear weights or whatever. And it’s going to break down horribly at the edges. But is there a rough measure?

Suppose a player is X points of OBP above league average and Y points of SLG above league average, and he has Z plate appearances. How many runs is that worth?

Thank you in advance, this would be very helpful to me.