Grading running backs can be tricky; rushing yards tell much of the story but remain a function of opportunity (itself an indicator of talent). Yards per carry sounds nice but often is more misleading than revealing. Last year at Smartfootball.com I analyzed team rushing games using rush success rate, and I will do the same today. Success rate has been around for awhile – The Hidden Game of Football wrote about it in the late ’80s and Football Outsiders has been tracking it for close to a decade. Everyone has their own unique definition, it seems; here is mine.
- I started with every play from scrimmage where a running back was credited with a carry. I then removed all instances of 3rd or 4th down carries where the back needed to gain more than 5 yards for a first down, since the primary goal in these situations usually isn’t to get the first down. However, on the rare occasions where a running back did convert for the first down, those plays were kept in the data set. This has only happened 20 times this season.
- On 3rd and 4th down, a success is a rush that gains a first down (or touchdown). A failure is every carry that does not result in a first down.
- On 2nd down, a success is achieved when the player gains at least 50% of the yards needed for the first down. This means that 2nd-and-8 runs are failures unless they pick up 4 yards; on 2nd-and-7, the running back must also gain at least 4 yards. A rush for one yard on 2nd-and-3 is a failure, and so on.
- On 1st down, a running back is credited with a successful carry if he gains at least 40% of the yards needed; therefore, four yards are required on 1st-and-10 before the running back is given credit. On 1st and goal from the 5, a two-yard gain would be considered a success.
The league average success rate by these rules is 49.8%. The table below lists all running backs with at least 50 carries, along with their number of rushes (which excludes the excluded carries), number of successful runs, and their success rate. The table is sorted by the far right column, which shows how many successes over 50% of their runs the player had. In the event of a tie, the player with more carries was ranked higher.
We can also look at things on the team level:
- The Falcons have the 2nd worst rushing success rate, which helps explain why they’re the most pass-happy offense in the NFL.
- Buffalo has an incredible running game but not much else. C.J. Spiller has been outstanding and Fred Jackson has been very good; unfortunately, the Bills have only outrushed their opponents by 105 yards and have allowed 17 rushing touchdowns compared to 9 by the offense.
- Having Tom Brady helps, but the New England running game has been fantastic this season. Stevan Ridley may not have the most challenging job in the world, but he still should be in the running for employee of the month.
- Last year (as of November 17th), Maurice Jones-Drew led all running backs in successful runs and had a solid 50% success rate. But on the team level the Jaguars were below average because of the other running backs, namely Deji Karim and his 37% success rate. This year, MJD has a 49% success rate while backup Rashad Jennings is at only 41%.
- If the Bears are expecting to win with their defense and running game, they can’t rank in the bottom five in rush success rate. Chalk that up to the offensive line, as both Matt Forte (57th in success rate) and Michael Bush (3.5 YPC) have had their struggles.
- Despite the very real evidence that the Jets running game is anemic — New York ranks 26th in yards per carry and five of the team’s eight rushing touchdowns came in garbage time/blowouts — Shonn Greene, Bilal Powell, and company (but not Tim Tebow) place the Jets 7th in success rate. They are not explosive players by any means, but the Jets lead the NFL on third-and-one conversion rate on rushing plays (12 of 13).
We also can rank teams by their rush success on defense:
- The 49ers may have fallen slightly from their perch atop the traditional rushing categories, but remain extremely stout against the run. That may have been why Jeff Fisher chose to have Greg Zuerlein kick a 54-yard field goal in overtime rather than try to convert on 4th and 1 against the 49ers.
- The Patriots are interesting. According to success rate, New England has the worst rush defense in the NFL, but the team ranks in the top 10 in both rushing yards and yards per carry allowed. That might merit further investigating. For what it’s worth, the Patriots also ranked last in rush success when I wrote this article last year. When advanced statistics show New England to be better than traditional metrics, we like to say that that’s why Bill Belichick is a genius. When the tide turns the other way, we question the statistic. Those Super Bowl rings come with perks.
- Similarly, the Steelers rank in the top 6 in both rushing yards and rushing YPC allowed, but are 31st in rush success rate allowed. It’s worth remembering that the data are not identical — traditional rushing stats include runs by non-running backs and third-and-long carries — but I’m a little surprised to see these results. Of course, that isn’t a bad thing, and might simply mean that the Steelers and Patriots are much worse against the run than we realize..
- Tampa Bay is currently having the most remarkable turnaround possible with their rush defense — the Bucs still rank 1st in both rushing yards and yards per carry allowed. They also come off as very strong in rush success rate.