I'd have to go with Bob Avellini over Mike Tomczak for worst QB in Chicago. His 69 interceptions vs. just 33 touchdowns makes you wonder how in the hell he lasted nine seasons. He didn't start every game for the Bears over that span (lucky for them) but if numbers alone tell the story, he didn't wow anyone in the games he did start.
What the article fails to mention is that not only was Mike Phipps largely abysmal for the Browns, but they traded a future Hall-of-Famer in Paul Warfield in order to draft him. Ouch!
Don't agree with Joe Kapp being the worst QB in Minnesota's history. Injun Joe will never rank up there with the all-time greats, but he did lead the Vikings to two playoff appearances, including the NFL championship in 1969. He also shares the record for most TD passes in one game (seven) which he accomplished against the Colts in 1969. He threw some strange looking ducks, but he wasn't all bad.