From ESPN. "For the last few seasons, the Houston Texans have continually threatened to make a run at the playoffs, but they haven't made it over the hump. There were always two problems. First, the Indianapolis Colts were in the way. And second, the defense was lousy. This season, both those problems have been solved: the Peyton Manning-less Colts are terrible, and the Texans' defense is finally playing well. In fact, Houston's defense is playing so well that the team should be able to overcome the losses of starting quarterback Matt Schaub and backup quarterback Matt Leinart and make the postseason for the first time in franchise history. The Texans actually rank No. 1 in the league in defense according to the official NFL standard of yards allowed per game. Now, the Texans' defense isn't quite that good. Houston happens to have played a particularly easy schedule of opposing offenses. But even if we use a metric which adjusts for opponent quality, it's clear that the Texans are much improved. Football Outsiders' DVOA ratings take into account success on every play, comparing results to a league-wide baseline that is adjusted for situation and opponent (more explanation here). Last season, the Texans' defense ranked 31st in the NFL. This year, it ranks seventh. That's one of the biggest year-to-year improvements we've seen in the 20 years for which we have play-by-play breakdowns -- although, amazingly, Houston hasn't had the biggest defensive improvement in the league this season. (In fact, they haven't had the biggest defensive improvement in their division. That honor belongs to the Jacksonville Jaguars, who will be the subject of a separate article on ESPN Insider this weekend.) Biggest Year-to-Year Improvement in Defensive DVOA, 1992-2011 Year Team DVOA Rank DVOA Y-1 Rank Y-1 Change 2011 JAC -14.1% 2 21.2% 32 -35.2% 1998 MIA -26.0% 1 7.6% 28 -33.6% 2009 DEN -7.3% 7 24.7% 31 -32.1% 1996 DEN -20.8% 3 11.0% 27 -31.8% 1998 OAK -19.4% 3 10.8% 29 -30.2% 2011 HOU -8.9% 7 21.0% 31 -29.8% 2001 STL -16.3% 5 13.5% 27 -29.8% 1996 GB -24.3% 1 4.8% 20 -29.1% 2009 NYJ -23.4% 1 2.5% 14 -25.9% 2001 CLE -17.0% 3 8.2% 25 -25.2% Before the season, in our book "Football Outsiders Almanac 2011," we pointed out that Wade Phillips has an impressive record for turning around defenses after he's hired. Some of this is just standard regression to the mean: Phillips has generally been hired to take over defenses that were so bad -- especially against the pass -- that they were bound to improve. Still, in Houston, we've seen perhaps Phillips' most successful renovation project yet. The run defense has improved nicely (from 24th in DVOA to 11th), but that's nothing compared to the pass defense, which was last in the NFL in 2010 and ranks fourth in 2011. Defenses Before and After Wade Phillips Before Phillips With Phillips Team Year DVOA Rank Year DVOA Rank BUF 1994 1.9% 19 1995 -6.8% 10 ATL 2001 9.3% 27 2002 -3.0% 12 SD 2003 11.0% 30 2004 -3.9% 12 DAL 2006 -0.9% 14 2007 -5.8% 11 HOU 2011 21.0% 31 2011 -8.9% 7 There have been two big reasons for this improvement. The first is an improved pass rush. Last season, the Texans ranked 17th in the league in adjusted sack rate, which measures sacks per pass play adjusted for situation and opponent. This year, even without Mario Williams for most of the season, the Texans are second in ASR. Third-year outside linebacker Connor Barwin has really blossomed with 8.5 sacks, and four other Texans have at least 4.5 sacks (Brooks Reed, Antonio Smith, J.J. Watt and, before he was injured, Williams). This pass rush improvement is one of the hallmarks of a Wade Phillips turnaround; of the five defenses listed in the table above, only the 2004 Chargers didn't see a significant jump in sack rate. The other big improvement has come from the addition of free-agent cornerback Johnathan Joseph. Joseph's impact can be seen from the splits of passes against Houston by direction. Joseph generally plays left cornerback, so he's on the offense's right side. The Texans allow just 4.2 yards per pass attempt on passes to the right, a yard better than any other team. They allow a completion percentage of just 48 percent on passes in that direction. By comparison, they allow 7.2 yards per pass on passes to the left (13th) and 8.7 yards per pass on passes in the middle of the field (17th). One problem for the Texans is that their defense gets weaker as the field gets shorter. Over the first 60 yards of the field, Houston's defense ranks second in DVOA. However, the Texans rank 17th between their 20 and 40, and 21st when the opposition is in the red zone. Then again, given what we found earlier this season -- that red-zone efficiency isn't a consistent trait from season to season or even game to game -- perhaps it's a good sign for the Texans that Houston's defense hasn't been as strong in the red zone. If the Texans play as well in the red zone as they have overall, their defense will improve over the next few weeks even as their offense struggles with a new quarterback. In fact, the Texans' defense is already on the upswing, powering a series of big wins the last few weeks. Through Week 6, the Houston defense ranked 12th in DVOA; in the six-week period since Week 7, Houston ranks second, behind only Chicago. Last week's victory over Jacksonville showed that Houston's opponents will now stack the box and dare T.J. Yates to beat them. Without a passing game to balance things, Houston's running game struggled. (Take out a 43-yard carry, and the rest of the Texans' carries averaged 2.3 yards.) If the passing game slows down, and the running game slows down, the Texans will be dependent on their defense if they're going to make it into the postseason and maybe even win a game there. Good thing that the trends suggest that the defense will be able to continue its strong play and take the team there."