To make sure that one position doesn't get overly favored during the drafting process (e.g., picking five bench point guards in a league that uses only one starting point guard), the Autopick algorithm uses a simple ratio that determines bench depth for each position based on the number of starters your league uses. So, the more starters you have per position the deeper your bench is for that position.

So, if your league uses one starting center, one starting forward, and three starting guards, your bench contains up to three times as many guards as it does forwards or centers.