Clausen was better throwing the deep ball but was no run threat. Quinn also had a stronger arm but not the accuracy shown by Book on throws under 30 yds. Book is very accurate there, a quick runner, and likely as fast as any going through his reads. Clausen just was not a runner and Quinn lacked in the accuracy dept. but was tough and a great leader. As far as making an offense efficient and a threat from all personnel, Book is as good as any. The only recent QB I would give a top grade to is Clausen for arm strength and accuracy. I like them all, but the move to Book makes the offense very, very threatening.