I'm seeing a LOT of citations of QB rating lately. Guys, look. I get that it's one number you can look at to get an idea of a player's passing ability. I like that aspect of it, don't get me wrong. The problem with it is that it sucks. It WAY overrates TD rating, which is more of a function of how bad a team's red zone offense is (in that if it sucks, the QB is forced to throw more TD passes) and how good their overall offense is (which a QB certainly contributes to, but in ways mostly covered in gaining yards). It also basically double-counts completion percentage in that a guy who completes a lot of passes will also have good yards-per-pass numbers (whereas a 1970s Kenny Stabler type could complete 50% of his passes and still be effective if all the completions are for 20 yards) (what made the Snake subpar in modern terms was his MASSIVELY high pick percentage).
On top of that - and this has been mentioned - it doesn't include sacks at all. Contrary to popular belief, sacks don't just happen to a QB. A guy like Matt Hasselbeck will often eat the ball instead of forcing it into traffic. Going back a few years, a guy like Brad Johnson got sacked a ton because he didn't check down terribly well. Dan Marino OTOH had some *very* iffy lines but still managed to post INSANELY low sack totals because he had a superhero level quick release. If Captain America had a release that quick, comic book fans would have complained he was unrealistic.
That's why I prefer Adjusted Net Yards per Attempt, which is listed in profootballref and is, well, pretty awesome. It's yards per catch, with picks counting -45 yards (the seminal football stats book The Hidden Game of Football figured out this was how much a turnover costs), TDs counting an extra 20 yards (which IMO is probably overrating them but hey, it is harder to complete a 2 yard TD pass to your 3rd string TE than it is to complete a 3rd and long pass to your FB for 2 yards, so they should be worth something), *and* bring sacks into the equation as well. Sacks are actually in there in two ways (not double-counted) - they're there both as failed pass attempts (which they are) and for the negative yards (which they are). It's everything QB Rating wishes it was and more.
I rag on Kolb below the break.
Kolb's ANYA? 4.5 That is ANYA-ese for "sucks". With that exact same squad, Michael Vick's ANYA was 7.3. That by the way was only 5th; Vick's MVP credentials, of course, were built up due to the combination of his running and passing abilities, but purely as a QB he was the 5th best QB by the metric last season. The guys who were better than him were guys you expect: Tom Brady, Philip Rivers, Aaron Rodgers, and Rofflesberger. Kolb's 4.5 ANYA would have been tied with the great Derek Anderson for 2nd worst in the NFL. Only Jimmy Clausen of the Panthers was worse. Bret Favre was (slightly) better with a 4.6. Hasselbeck "earned" a 4.9.
Now don't get me wrong, it's still better than Whitehurst's 3.8 or Tavaris Jackson's 2.8, but look... when the guy to get is a 4.5 and he's going to cost you a 2nd and a good young player... you can find someone better. Like Chad Henne or Tyler Thigpen, one of whom could easily be a FA come the end of August (4.9s each). Or Jon Kitna, who went from holding a clipboard in 2009 to posting a 6.0 last year. 4.5 is pretty damn close to replacement level if you ask me.
And by the by, that 4.5 is also Kolb's career ANYA. As awesome as he was in a couple starts in 2009, he was crap in garbage time his first two years. Maybe he's better now than then, but it's equally likely that he simply wasn't as good as people thought he was as a fill-in in '09. The biggest sample size we have, the closest thing which we can use which approximates his real value, shows him as a 4.5 ANYA player on an offense where another QB was far, far better. Playing that same game with Jackson gives you a 5.0 career ANYA - not great, but my point is that it doesn't have to be great to beat Kolb.
We can keep playing this game! Derek Anderson, whom I think everyone can agree sucks, has posted ANYAs of 4.5, 2.2, and 4.5 over the past 3 years. His career mark, which includes his one awesome season of 2007, is 4.8. Trent Dilfer, whom I don't think anyone remembers as a great QB, had a career mark of 4.4 (5.4 in Seattle, though, 9.2 in Tampa, and 6.5 in Cleveland). Alex Smith has a career 4.4, with a 5.6 last season. Sam Bradford's grossly overrated checkdowny rookie year got him a 4.7. Jon Friesz was a 5.0 for his career (4.5 during his crap stint in San Diego though). Kordell Stewart had a career 4.5. KORDELL STEWART, PEOPLE.
Bottom line, even if Kolb suddenly turns into an NFL-caliber starting QB, this was a horrendous move by the Cards. If he performs at a similar level to Derek Anderson, fans will probably call it a disappointment... but really, that's probably his 50th percentile.