Week 4: Colts Defense by the Numbers

Each week during the season, I will be walking through the data from the previous Colts game analyzing the numbers to form a sort of “what happened” narrative as well as comparing the Colts against all other teams in the league. For a glossary of the stats listed, reference Season Stats. Thanks to Pro Football Reference, NFL.com, Football Outsiders and the nflFastR project for being awesome sources of weekly data.

Another brilliant game from the defense.

The ability to move the ball is measured by drive success rate (DSR) and prior to their last drive, the Bears only mustered 11 first downs on 20 series for a wretched 55% DSR. Had the game ended at that point, that would have been the worst mark of any team this year. But, the garbage time TD allowed them to fall backwards into an overall 64% DSR . . . which is still really bad and the worst of any team on the week.

TEAM TOTALS

By points per drive, the Colts defense ranked 4th on the week, but they were 1st in expected points per drive against (xOPPD), which uses opponent DSR, avg starting field position and yards on successful series to determine what a team should have scored. I bring up that obscure custom stat as it is the most predictive stat for future wins and on the season the Colts defense is #1 and it’s not even close.

In fact, on the year the Colts are #1 in just about every stat in that table. It’s literally easier to list the things they don’t lead the league in:

• #2 in weighted total success rate (wTSR)
• #2 in explosive play volume (Expl plays)
• #9 in avg yards to gain on 3rd down (3rd ytg)
• #7 turnovers (TO)
• #20 in first downs by penalty (Pen 1st / Yds)
• and **sigh** #2 in time of possession (TOP)

PASS TOTALS

Against the pass, the Colts held Nick Foles to the 6th worst efficiency on the week (epa/db). They were even better by passing success rate (#2 PSR, #2 wPSR), which means they forced da Bears to have proportionally more negative value pass plays than all but 1 team (NE).

Those high defensive rankings were driven by limiting passing first downs to only 28% of dropbacks (1st/db, rank 3rd) and giving up only 5.6 yards per passing play (ny/db, 6th). In addition, Foles managed a 61.9% completion rate but when accounting for distance and field position, that was 5% below expected (cpoe against, 5th).

Again, on the season, the Colts defense leads in just about all passing stats: EPA/db, PSR, wPSR, Pass Yds, INT, 1st/db, NY/db.

RUSH TOTALS

In week 4, the Bears only gained 28 yards on 16 carries, which is a pathetic 1.8 yards per attempt. Only 2 of those carries added positive value (both first downs) resulting in a 12.5% success rate (RSR). Weighting that for situation improves it slightly to 16.3% (wRSR), but that is still the 3rd lowest mark of the week.

On the season, the Colts defense isn’t #1 in any of these measures, but they are top 10 in wRSR against (#6), RSR against (#5), 1st downs per carry against (1st/c #9), ypc against ( #5) and EPA per carry against (epa/c 10th).

CONCLUSION AND LOOK AHEAD

This was pretty much domination from beginning to end and through week 4 the Colts have clearly put up the best defensive numbers of any team. However, that does not adjust for opponent, so until we battle some dominant offenses, it may be best to reserve judgement.

Next week will be a test of the defense as the Colts visit the Cleveland Browns and their 9th ranked offense (by DVOA). The Browns average over 30 points a game and are easily in the top 10 of every team offensive production stat I care about (and 13th in TOP, which I don’t care about).

They are ridiculous at rushing, averaging almost 200 yards a game at 5.9 yards a clip. Those are both league high numbers as is the implied 34 carries per game. Over 30% of their rushes result in a first down or TD (3rd best). They run on first down more than any other team (67% of plays) and they average 7.1 yards when they do (1st in NFL). If the Colts defense can’t limit their run game on early downs, the Browns will be a juggernaut.

Given all that, it shouldn’t be surprising that the Browns pass the least of any team (49% of scrimmage plays). Their overall passing efficiency is good (11th EPA/db, 12th wPSR) but they don’t convert many first downs through the air (20th 1st/db) and their yardage efficiency is poor (26th NY/db) which should mean longer 3rd down situations and the data bear that out as CLE has the 7th longest 3rd down yards to gain of any team (7.6).

I’m trying to see the silver lining here and it’s tough. Cleveland is going to score on us. I just think that is reality.