Rex Ryan is a good football coach.

Nobody could really argue too hard against that statement in 2009, and by 2010, it was even more evident that Ryan was doing something right.

Sure, Ryan has always had his shortcomings as a coach -- be it a young Mark Sanchez's quarterbacking his Super Bowl contender or, well, any quarterback since he took the job in 2009 -- and his offense overall was never anything intimidating (more on that later). But Ryan rode one of the best defenses in recent history to consecutive AFC Championship games in his first two years wearing green.

Things have gone downhill since those first two seasons, and the Jets have been, at best, 8-8 for four straight campaigns. Now, though, after a 4-12 season and a 26-38 record overall record with the organization in the last four years, Ryan is on the out.

Was it the right call for the Jets?

The Early Days

It always "felt" like the Jets had a special defense back in 2009, and according to our metrics, those feelings were true. According to Net Expected Points (NEP), which quantifies how well a team or player performs above or below expectation, the 2009 Jets were one of the best defenses since we started keeping tabs on that kind of thing back in 2000.

Adjusted for strength of schedule, the 2009 Jets defense posted a Defensive NEP per play of -0.15. That means that they basically took 0.15 points off the board each time their opponents snapped the ball. Sound like an impressive number? It is. The 2009 Packers, the second-best defense according to our metrics, were at -0.08. Also, since 2000, that's the sixth-best mark a team has maintained for a full season.

Speaking of great defenses since 2000, the top four overall seasons, amazingly, all come from the same organization: the Baltimore Ravens.

The Ravens of 2006 posted an Adjusted Defensive NEP per play of -0.19, the best in our database, and the 2008 squad was at -0.18. Oh, yeah, Ryan was their defensive coordinator from 2005 to 2008. The 2003 Ravens (-0.17) and 2000 Ravens (-0.15) round out the top four, and Ryan was the defensive line coach for each of those seasons.

Ryan knows defense, but did it really translate when he went from coordinator to coach?

Gang Green Defense

Well you already know it did in 2009, but what about the rest of his tenure?

Here are the Jets' Adjusted Defensive NEP per play (along with Adjusted Defensive Passing and Defensive Rushing NEP per play) marks and ranks while Ryan has been at the helm.

So, a few things. The first three years were quite impressive on the defensive side of the ball. In two of the three seasons, the Jets boasted the best overall defense, per our metrics, and even though they relinquished that crown in 2010, they had the best run defense in the league.

Since then, things have gone downhill drastically, and the Jets have been, more or less, hovering around 16th in the various categories. This year, though, things got worse, and the Jets ranked 26th in defense. Even their rush defense wasn't what it seemed.

Sure, they ranked fifth in rushing yards allowed (1,489) and sixth in yards per carry against (3.8), but those numbers are a bit misleading when factoring in volume. The Jets saw just 393 carries against, seventh-fewest in the league. While the raw numbers suggest they were a top-six type of run defense, the metrics don't support it.

Their Defensive Rushing NEP, the cumulative version of the metric, was -6.59, meaning they denied their opponents about a touchdown over the duration of the season. That number ranked 15th. But when factoring in the low volume, it becomes even less impressive -- not that 15th overall is something to feel great about with a defense-first coach.

I'm all for Ryan's defensive potential, but it's just evident that his squad didn't get it done on that side of the ball in his final three years with the team. Still, it wasn't quite as bad as the offense.

What About the Offense?

Here's the same table for Ryan's Jets but with offensive metrics.

Yikes. Not once did the Jets crack the top 20 in overall offense in the last six years, and in four of the six, the Jets were 27th or worse with the pass.

The run game returned to formidable this year, but in the three years prior, it was just like the offense overall: outside the top 20.

We can go into why the offense struggled for days and days, but the fact is that the Jets haven't had a serious offense since 2006, when they ranked 12th in Adjusted NEP per play (0.02). Place the onus on Ryan if you will, but in fairness, the offensive woes predate Ryan's arrival.

Based on this, to me, firing Ryan was the right choice. Not necessarily because I think he's a bad coach but rather because Ryan had failed to reach his defensive potential with the Jets for the past three seasons for myriad reasons and because offensive output like that is inexcusable for that long.

Either the Jets are incapable of getting him the players he needs, or he isn't able to do Rex Ryan things with what he's been given. Those sound similar, but they're very distinct, and with the way the Jets have struggled, starting over has to be considered the right call.

Ryan will find work, and there's no reason to think he can't get back to his elite defensive days if he finds the right team, but it's evident that the Ryan-Jets relationship just needed to end for both parties to move on to --hopefully -- better things for both.