I think QB play does erode over the course of a game due to stamina, but other players' play erodes MORE due to stamina, so over the long run it tends not to matter all that much.
Stamina loss for a QB also seems directly tied to the number of throws, though, and I think that's part of the reason why if you average 25-35 passes a game your QB will probably look fine, and if you average like 40+ throws a game your qb's completion % usually don't look too hot. But this isn't any scientifically backed thing, just random observations drawn together to a simple logical "conclusion"
I think numbers-wise most teams simply don't have the need for a backup who'll get like 8 throws a game, especially considering, as Galkuris said, most backups will be so inferior to the starter that your passing gameplan can get thrown out of whack.
Stamina loss for a QB also seems directly tied to the number of throws, though, and I think that's part of the reason why if you average 25-35 passes a game your QB will probably look fine, and if you average like 40+ throws a game your qb's completion % usually don't look too hot. But this isn't any scientifically backed thing, just random observations drawn together to a simple logical "conclusion"

I think numbers-wise most teams simply don't have the need for a backup who'll get like 8 throws a game, especially considering, as Galkuris said, most backups will be so inferior to the starter that your passing gameplan can get thrown out of whack.





























