An idea I have for looking at historical QBs

If I ever get the time / find a point in the future where I need to complete a report for class but get a major case of the procrastinations, I'll see if I can do this with all Seahawk quarterbacks or something, but here's my idea: cross-era equivalencies. What would Dave Krieg's stats from 1984 look like in the context of 2010? I know this has been done before, but I don't think it's been done using standard deviations. I'll try and explain my method here and see if people think if it has any legs.

In 1984, Dave Krieg put up the following numbers for a team which went 12-4 despite not having a RB rush for more than 350 yards that year:

16 G, 270-480, 3671 yds, 32 TDs, 24 Int, 40 Sk, 314 yds lost, 5.6 ANY/A

And just for the heck of it, here's Dan Marino, who set a record for TDs which was only recently surpassed:

16 G, 362-564, 5084 yds, 48 TDs, 17 Int, 13 Sk, 120 yds lost, 8.9 ANY/A

How does that compare with the league? I'm going to figure that out using rate stats for attempts per game, completion percentage, yards per completion, touchdown and INT percentage, sack percentage, and finally yards lost per sack. Instead of doing this on a percentile basis - that is, saying that Krieg threw 35% more passes than the average QB, I'm going to use standard deviations. The sample size might be a bit on the small size for this metric (using players with 50 or more passing attempts, I get 54 guys I can use for this study) but the idea still holds: essentially, two thirds of all players will be between 1 standard deviation from the league average one way or the other, with 95% within 2 standard deviations.

The average number of attempts per game, taking into account all of these guys, starters and backups (I wish there was a better way to do this but one issue is that there were just a lot fewer passes thrown overall 26 years ago and I don't want to stray from the st-dev idea for now) is 21.90, with the standard deviation at 8.00. That means that Dave Krieg, with his 30 attempts was 1.01 standard deviations above the norm for the year. Running these numbers with both QBs:

Krieg: Att/G: +1.01, Com% +0.41, Y/C +0.72, TD% +1.65, Int +0.21, Sk% -0.38, Y/Sk +0.20

Marino Att/G: +1.67, Com% +1.49, Y/C +1.24, TD% +2.69, Int -0.62, Sk% -2.20, Y/Sk +1.36

The big thing that sticks out already is that *huge* touchdown percentage number for Marino. A lot of younger fans might not remember that Dan the Man was also widely regarded as having the quickest release in the history of the game. Although never a very mobile quarterback, the man *never* got sacked. As you can see, Krieg was no slouch either, finishing above average in everything but interception percentage and in amidst the elites in TD% and attempts per game.

Now on to 2010. On average, teams attempted only around 2.9% more passing plays per game this year compared to 1984. That means, in order to find a similar cohort, I'll be looking at guys who attempted 51 or more throws. For what it's worth, this small change did not drop any QBs off the list who would have been on had I kept it at 50, although there's a case to be made to include Charlie Batch, who attempted just 49 passes but was also sacked 4 times. Probably not a huge difference, though, and in any case the 2010 cohort is 52 guys large. The averages and the deviations look like this:

Att/G: 28.05/8.06, Com% 59.5/4.8, Y/C 11.5/1.5, TD% 4.1/1.6, Int% 3.2/1.4, Sk% 6.7/2.5, Y/Sk 6.6/1.1

Okay, now for the fun part. Dave Krieg's 1.01 standard deviations above the norm gives him 36.2 attempts per game and 579 overall. The rest of the numbers for good old Mudbone:

Krieg, normalized to 2010: 16 G, 356-571, 61.5%, 4474 Yds, 39 TDs, 20 Int, 33 Sk, 213 SkY, 6.7 ANYA

Not a bad showing! Normalized to 2010, 1984 Dave Krieg would have finished tied for 6th in attempts with Matt Ryan and 4th in total passing between Drew Brees and Matt Schaub. Interestingly, his 39 TDs would actually have led the league, and although many of us think of Krieg as being the victim of the "blitzkrieg" attack, he would only have been 11th in the league in sack yardage, behind Ben Roethlisberger and just ahead of Michael Vick. All in all, that adjusted net yards per attempt number of 6.7 is pretty much exactly even with Schaub.

Now for added fun, let's look at Marino:

16 G, 443-664, 66.7%, 6,196 Yds, 56 TDs, 10 Int, 8 Sk, 65 SkY, 10.1 ANYA

Whoa. 8 sacks. 6,000 yards passing, more than 1,000 more than anyone else in NFL history (right now the real 1984 Dan Marino holds that record). 9 more TDs than Tom Brady had in 2007. Peyton Manning's 2004 actually comes sort of close to 1984 Marino's normalized stats (9.8), which shows how freaking amazing Peyton's Place was that year.

I just want to make this clear: this is not what Dan Marino would have done in 2010 if he was 24 years old, had the same team around him, and so on. This is what Dan Marino *did* do, relative to his league. Although the league has moved from being one where the run set up the pass to the other way around, Marino's raw totals from that year still look impressive today. Through the lens of era modifiers, that was a year sort of like Babe Ruth's 1920 in baseball.