Looking back, were the Colts really ready to make the switch? Not really, but few teams ever are.
Before the arrival of a completely new coaching staff, the Colts ranked 28th in scoring defense and 25th in yards allowed during the 2011 season. In 2010, they ranked 23rd and 20th, respectively, and the numbers were rarely ever good in the previous seasons before that.
The Colts then made the switch in 2012, and the numbers didn't improve drastically, but the defense as a whole looked worse. They gave up 374.3 yards and 24.2 points per game, and both Pro Football Focus (subscription required) and Football Outsiders had them ranked as the second-worst defense in the league using their respective scales.
So what was the problem?
As it usually is during the first few years, the Colts didn't have the right personnel for the defensive scheme. Robert Mathis has proven that he's a good fit this year, but back in 2012, both him and Dwight Freeney struggled with the change from defensive end to outside linebacker—particularly in run defense.
Meanwhile, the defensive line struggled as well, with players like Cory Redding, Antonio Johnson and Ricardo Mathews not comfortable in the defense, and the run defense once again struggled because of it. Overall, the Colts allowed 137.5 rushing yards per game last season, which was 29th in the league.
This is an issue with plenty of teams as they make the transition to a 3-4 defense. We've seen it this season with the Philadelphia Eagles as well. While their offense has improved with Nick Foles under center, they're lack of personnel fit for the 3-4 scheme has kept their defense from turning things around, as you can see here.
|Eagles Defense 2012 (4-3) vs. 2013 (3-4)|
|Year||YPG||Rank||Pass YPG||Rank||Run YPG||Rank||PPG||Rank|
For the Colts, the 2013 season has seen some improvement. They're holding opponents to 362.6 yards and 22.8 points per game, with the latter being a pretty good improvement. Takeaways have also gone way up, already forcing 21 turnovers this season as opposed to just 15 in all of 2012.
However, there are still some areas that they have to address with this new scheme.
The first one is clearly the pass rush. Mathis has been fantastic, grabbing 16 sacks and 33 quarterback hurries (h/t Pro Football Focus), but no other player has more than four sacks or 19 hurries. Many have taken notice, including Football Outsiders, which has the Colts ranked 14th in the league in terms of pass rush.
Bjoern Werner is supposed to be the guy to help get pressure on the quarterback, but he hasn't been the best option this season due to making the transition from a college defensive end to an NFL outside linebacker.
But we've seen some improvement over the past couple of weeks, with Werner even grabbing a sack against the Houston Texans this past week, his first since Week 2 against the Miami Dolphins. But he's still raw, and he needs more time to get accustomed to the position.
The other major issue with the defense this season has been the secondary, which has been incredibly inconsistent. Injuries and the lack of a pass rush are parts of it, but at the same time, some bad teams have burned the Colts deep.
Vontae Davis has had some fantastic games, like the one against the Denver Broncos, but then he finds ways to get burned in others.
Antoine Bethea, who has been such a popular player over the years, has hit a wall, and he's arguably had the worst season of his career.
Meanwhile, players like Greg Toler and LaRon Landry vie to stay on the field, while other backups simply struggle.
The secondary could be a bigger concern after this season. Davis and Bethea will be free agents, and there's not a good chance that either stay in Indianapolis. That leaves the team with few options, so it will have to focus on that area for 2014.
Some fans may be frustrated after watching the New Orleans Saints turn things around so quickly this year with Rob Ryan as their defense coordinator. But there has been clear improvement on defense, with several players, including Mathis and Redding, getting more comfortable in the defensive scheme.
With a lot of cap space after this season, the Colts will likely go after more defensive free agents fit for the 3-4 scheme. The improvement has been slow, but it's there, and the Colts could eventually have a solid defense for the first time in a long time with the right roster moves and coaching.
Follow Tyler on Twitter @TylerDBrooke