Plenty of words have been used to define Houston Texans coach Bill O'Brien.

During the HBO series "Hard Knocks," O'Brien was the crusty coach who needed a bleep button for his language. When he benched starting quarterback Brian Hoyer in Week 1, he was the impatient drill sergeant with the quick hook. During a 1-4 start, he appeared lost on defense and struggling on offense.

But the best word to put next to O'Brien's name is "underappreciated." His style and methods might be somewhat unconventional, but there's no denying that he has put together two good seasons of coaching. He was 9-7 last year with Ryan Fitzpatrick most of the season. This year, he won the AFC South using four different quarterbacks.

This week, everyone in the NFL is adjusting to Tuesday's news that Philadelphia Eagles owner Jeff Lurie fired Chip Kelly after 47 games. Lurie saw a troubling more-is-less trend brewing with Kelly -- that is, the more power he gave his coach in personnel, the less effective Kelly was at winning football games. Back-to-back 10-win seasons dropped to 6-9 this season with an offense ranked toward the middle or bottom of the pack in most statistical categories.

In short, the Eagles were trending downward.

The Texans, thanks to O'Brien, are trending upward because he is getting more out of less on offense. Last year, Fitzpatrick turned around his career playing for O'Brien, completing a career-best 63.1 percent of his passes and throwing 17 touchdowns versus eight interceptions in 12 games. This season, Fitzpatrick is having a career year for the New York Jets.

It's too early to tell if going to Hoyer over Fitzpatrick is an upgrade, but there is no question Hoyer is doing well with O'Brien, despite the opening-game benching. Hoyer's completion percentage is a career-best 60.5 with 18 touchdowns and six picks in 10 games.

With Hoyer now cleared from concussion protocol and set to return as the starter on Sunday, O'Brien can start preparing for a wild-card playoff game against the Kansas City Chiefs, Fitzpatrick's Jets or the Pittsburgh Steelers.

Ryan Fitzpatrick, who's enjoying a career year with the Jets, might face his former coach in the playoffs. Michael Ainsworth/AP

One underrated aspect to O'Brien's 17-14 start as an NFL head coach is how well he understands the value of defense. Though the Houston unit looked shaky in the first half of the season, defensive coordinator Romeo Crennel has quietly done exactly what Andy Reid did with the Chiefs' defense. The Texans have shut down teams, allowing just 12.8 points per game over their past eight contests.

All you have to do is look at the standings to understand the value of defense. With one exception -- the Dallas Cowboys, without Tony Romo -- teams projected to draft in the top 17 of next year's draft are giving around 24 or more points a game. The Texans' average for the entire season is 20.5.

Having the luxury of a defense that keeps a team in games gives an offensive coach like O'Brien the chance to squeeze as much out of the offense as possible to win games.

For the moment, O'Brien is both lucky and cursed.

He's lucky the AFC South is so bad that he can win despite not having great quarterback play. The Texans haven't been burdened by a tough schedule; and when they have played good teams, they have largely struggled. Houston was 2-6 against teams with .500 records or better last year and 2-4 this year.

He's potentially cursed, because getting in the playoffs put the Texans in the bottom 12 of the first round, where it's hard to draft quality quarterbacks. Add in the fact that it is rare for top quarterbacks to hit the free-agent market and it isn't hard to envision Houston's lack of a long-term answer at quarterback eventually catching up with the franchise.

With what he has had at quarterback, O'Brien will be hard-pressed to find himself in many award discussions after two years. Mike Sando ranked the five best coaching jobs this season, and O'Brien's name didn't surface. That's understandable. O'Brien didn't put up a 14-game winning streak like Ron Rivera. He can't match Bruce Arians' 13-2 season and explosive offense at Arizona. He didn't win 10 straight after starting 1-5, like Reid did. And his turnaround wasn't as surprising as Jay Gruden's in Washington or Todd Bowles' in New York.

But for now, O'Brien at least has put the Texans back in contention while going week-to-week figuring out what to do at quarterback. And for that, he deserves some recognition.