There are plenty of ways to define consistency at the quarterback position. Perhaps you see consistency as a quarterback playing at the same level game in and game out. Maybe consistency, to you, links to longevity -- a quarterback who can play at the same level for a long time would be considered reliable.
There's no single way to define the term in football, but we've got a pretty interesting statistic here at numberFire called Success Rate that can at least give us an idea of quarterback consistency.
Essentially, Success Rate takes our Net Expected Points (NEP) metric and looks at it in a black and white way. When a player has a positive play in terms of NEP -- no matter how big or small -- it's deemed a success. When he doesn't, it's a failure. The percentage of positive plays a player makes, then, is his Success Rate.
Take a look at the bottom-10 quarterbacks (minimum 200 drop backs) from last season, sorted by Success Rate.
| Full Name | Passing NEP | Per Drop Back | Pass Success Rate |
|---|---|---|---|
| Blake Bortles | -97.97 | -0.18 | 38.30% |
| Charlie Whitehurst | 2.15 | 0.01 | 39.90% |
| Drew Stanton | 7.50 | 0.03 | 40.24% |
| Derek Carr | -40.94 | -0.07 | 41.00% |
| Josh McCown | -31.02 | -0.09 | 41.87% |
| Nick Foles | 15.15 | 0.05 | 42.68% |
| Russell Wilson | 47.65 | 0.10 | 42.91% |
| Mike Glennon | 0.55 | 0.00 | 42.92% |
| Geno Smith | 5.25 | 0.01 | 43.29% |
| Robert Griffin III | -36.84 | -0.15 | 43.32% |
The first few names on this list -- the least consistent guys throwing the ball last year -- shouldn't surprise you. Blake Bortles, per Passing NEP, was the worst quarterback in the NFL last season, compiling a -97.97 total. That ranked sixth worst among all quarterbacks since the turn of the century.
There's actually a relatively significant jump from Bortles to Charlie Whitehurst, the second most unreliable passer in the league last year. However, Whitehurst was far more effective on his throws, averaging 0.01 Passing NEP per drop back (the NFL average last year among starters was 0.10). This -- and same with the next person on the list, Drew Stanton -- tells us that he was a boom or bust guy, overall. It's just his boom far outweighed someone like Bortles, who was insanely inefficient with each drop back.
Derek Carr was the fourth least reliable quarterback, and because of this, I'm bound to see Raider fan hate in the comments section of this article. No, really -- just take a look at the stuff readers said about this article I wrote on Carr earlier this offseason. The fact is, he wasn't an efficient passer last season, and his numbers clearly reflect that. Perhaps new weapons will help him out a bit, though, in 2015.
The biggest surprise on this list, however, is Russell Wilson. After enjoying two very efficient years as an NFL quarterback to start his career, Wilson's 0.10 Passing NEP per drop back was not only half as effective as he saw during his rookie campaign, but it ranked tied for 13th in the NFL. That's not awful, no, but his Success Rate of 42.91% kind of was. As was the case with Stanton and Whitehurst, Wilson was able to make big, clutch plays to increase his overall Passing NEP total, but play by play, things weren't all that great with his arm (not his legs, which were ridiculous a season ago) last year. That'll be something to watch as we enter the 2015 season.