We've seen a little bit of everything under center through four weeks of the 2023 NFL season.
Brock Purdy leads the NFL in Total QBR over Tua Tagovailoa, Josh Allen, Patrick Mahomes and Justin Herbert. Aaron Rodgers is out for the year because of a torn left Achilles. Joe Burrow has struggled as he battles a calf injury. And Joshua Dobbs -- a late-August acquisition for Arizona -- is among the most efficient passers in the league, while Baker Mayfield -- on his fourth team in three years -- has the Bucs on the playoff trail.