As a rookie at age 23, Sam Bradford averaged 4.73 Adjusted Net Yards per Attempt ^[1]Defined as Passing Yards + 20 * PTDs – 45 * INTs – Sack Yards Lost, all divided by total dropbacks (i.e., including sacks). at a time when the league average ANY/A was 5.73; as a result, we could say that Bradford had a Relative ANY/A of -1.00. The next year, he averaged 4.49 ANY/A with a RANY/A of -1.41. In 2012, he was at 5.64  and -0.30, and in seven games in ’13, he averaged 6.10 and +0.23.  In other words, he’s been mostly below-average for his career.

In order to calculate his career RANY/A to-date, we need to weight his production by his number of dropbacks, which were 624 in ’10, 393 in ’11, 586 in 2012 and 277 in his last season of play. Do the math, and Bradford has a career RANY/A of -0.68 entering the 2015 season. But could he have a breakout year playing with Chip Kelly in Philadelphia?

I decided it would be interesting to look at the question from the reverse angle: how many of the quarterbacks that were really good at age 27 were not so good before that? I defined “really good” to mean a RANY/A of +1.00 on at least 224 dropbacks since 1970 (i.e., a quarterback who had an ANY/A average at least one full yard better than league average, had a significant number of dropbacks, and did so since the merger). I also required that such quarterback had at least 500 career dropbacks through age 26 (Bradford has 1,880 career dropbacks prior to the 2015 season.)  There were 24 quarterbacks who met those criteria.

The best RANY/A season since the merger by an age 27 quarterback was Craig Morton; the Dallas quarterback hadn’t played much prior to 1970 (just 615 career dropbacks), but he had been effective in limited time before then (a career RANY/A of +1.58 prior to the ’70 season).

The second best age 27 season came from Boomer Esiason, in his MVP season of 1988. That year, he had 418 dropbacks and averaged 2.77 ANY/A better than the league average; prior to 1988, he had 1,531 career dropbacks, and a career RANY/A of +1.32. The table below shows that data for all 31 quarterbacks:

As you would suspect, the majority of quarterbacks who had great seasons at age 27 were pretty good before age 27, too. In fact, only one quarterback with any sort of previous workload had a worse career RANY/A than Bradford through age 26, and then had a breakout year at age 27. And that player was also a former number one pick: Terry Bradshaw.

And the next worst QB after Bradshaw to break out at age 27 would be… Troy Aikman. Oh, and John Elway also had a below-average RANY/A through age 26. ^[2]Oh, and another first overall pick, Eli Manning, had his first Pro Bowl season at age 27.  There is nothing special about “age 27”, but as I’ve written before, quarterbacks selected first overall usually go to bad teams and are expected to be saviors; sometimes, it takes them awhile to break out.

Bradshaw, Aikman, and Elway were struck on really bad teams; Bradford has been, too, especially at wide receiver. So the conclusion here is really in the eye of the beholder. If you don’t believe in Bradford, you’d note that there’s only one quarterback who was as bad as Bradford was through age 26 and then broke out at age 27, and that happened 40 years ago. Nobody in recent history comes close to fitting that description. Take a look at the table, and sort by year: nobody in recent memory that was very good at age 27 was anyone near as Bradford has been through age 26.

On the other hand, it would hardly be considered unusual for a first overall selection at quarterback to take some time to break out. Then again, don’t blame me if I’ve convinced you that Sam Bradford is poised to have a breakout season.