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 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.

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.

Takeaways

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.