What History Tells Us About Ryan Tannehill’s Potential as a Franchise Quarterback

One year ago, Ryan Tannehill wasn't the answer at quarterback for an NFL team, as the Miami Dolphins traded he and a sixth-round pick to the Tennessee Titans for a fourth- and seventh-round pick.

Now, he is getting paid as if he is the answer at quarterback for an NFL team.

Tannehill took over as the starter in Week 7 for Tennessee and ultimately helped lead them to an AFC Championship appearance. At one point, they had a 61.56% chance to beat the Kansas City Chiefs and represent the AFC in the Super Bowl.

Even though Tennessee fell short, they found their quarterback. What should we expect from Tannehill?

Tannehill's Turnaround

Prior to the 2019 season, Tannehill had never performed above the NFL average in Passing Net Expected Points (NEP) per drop back in his career, and he only once was above average in Passing Success Rate.

If you're not familiar with NEP, think of it this way: a 10-yard completion is always better than a 5-yard completion in the yardage column, but if the 5-yarder comes on 3rd-and-2, it's a bigger play than a 10-yarder on 3rd-and-22. Those plays add up over a year and help separate the NFL's best from the NFL's...not quite as good.

Team Year Drop
Pass NEP Pass NEP/
Drop Back
Diff. Success
MIA 2012 519 -22.63 -0.04 0.06 -0.10 43.74% 46.55% -2.81%
MIA 2013 647 -2.44 0.00 0.05 -0.05 44.82% 45.91% -1.09%
MIA 2014 637 46.72 0.07 0.08 -0.01 50.71% 46.91% 3.80%
MIA 2015 632 33.99 0.05 0.11 -0.06 44.15% 46.87% -2.72%
MIA 2016 417 39.14 0.09 0.12 -0.02 45.32% 47.02% -1.69%
MIA 2018 309 -26.56 -0.09 0.11 -0.19 42.07% 47.57% -5.50%
TEN 2019 333 75.74 0.23 0.10 0.13 52.55% 46.68% 5.87%

Tannehill thwarted the average in both categories this year, his career-best season. Perhaps a change of scenery was all he needed.

What went differently? Well, for one, via FantasyADHD, Tannehill upped his average target depth from 8.4 as a Dolphin to 9.5 as a Titan. He also turned in a very nice 6.9% touchdown rate in 2019 compared to 3.9% in his career prior. That led to an adjusted yards per attempt boost from 6.7 to 10.2.

That 10.2 adjusted yards per attempt mark was historically good: it actually ranked him sixth all-time. So, the regression monster is probably lurking down in Tennessee.

Let's jump back to Passing NEP per drop back, numberFire's go-to stat for quarterback efficiency. Since 2000, we have seen 470 different instances of a passer posting at least 200 drop backs in consecutive seasons. Tannehill's 0.31-point increase (from -0.09 to 0.23) is the sixth-biggest increase in that sample. Here are the 12 biggest jumps.

Full NameYear to YearPass NEP/
Drop Back
Following Season
Pass NEP/Drop Back
Jared Goff2016 to 2017-
Drew Brees2003 to 2004-0.160.300.46
Nick Foles2012 to 2013-0.050.310.36
Tom Brady2006 to 20070.110.430.32
David Garrard2006 to 2007-
Ryan Tannehill2018 to 2019-
Andy Dalton2014 to 20150.050.350.30
Carson Palmer2004 to 2005-
Jake Plummer2002 to 2003-
Josh Freeman2009 to 2010-
Blake Bortles2014 to 2015-
Mark Brunell2004 to 2005-

That's quite a mixed bag. We've got stars on the list -- Drew Brees and Tom Brady -- and then a lot of question marks or clear anomalies.

If we scale back the improvement threshold to a Passing NEP per drop back boost of 0.15 year over year, we've seen that happen 53 times. Of those 53 passers, 45 had at least 100 drop backs the following year (two years removed from the down year and one year removed from the huge improvement).

Of those 45, only 5 quarterbacks increased efficiency a second straight year, and less than half (19; 42%) played even to the league average level the following year.

The average per-drop back fall off from quarterbacks who saw a one-year increase of at least 0.15 Passing NEP per drop back? 0.16 points back south. Whew.

That still leaves some wiggle room for Tannehill to be an average NFL passer, but such huge efficiency jumps are almost always met with disappointing seasons the following year. Just two quarterbacks -- Peyton Manning in 2003 (another 0.18-point boost) and Brees in 2007 (0.16) -- built on these breakout years in a meaningful way. The rest of the pack was lucky to tread water, and most sunk again.


Tannehill's 2019 season was good enough that -- if that's what he gives Tennessee moving forward -- they can be a factor in the AFC for years to come.

He still took enough sacks and had enough turnovers that he didn't play quite at the level of the NFL's true elite, but he was better than what Marcus Mariota had given them during his tenure as the team's starter.

There are clear causes for concern here, too, as we know Tannehill had a high touchdown rate, and touchdown rate tends to stabilize toward career averages.

Ultimately, history suggests that unless Tannehill is Drew Brees, Peyton Manning, or Tom Brady, he is going to take a step back and disappoint in 2020 if expectations are that of a 2019 repeat.