I appeared on Chris Harris’s podcast today, talking yards per carry and game scripts. You can listen to it here.
In 2008, Jamaal Charles had 67 carries and averaged 5.33 yards per carry. Those 67 carries represent 5% of Charles’ career attempts to date (excluding playoffs). That season, the NFL league average was 4.20 yards per carry, which means Charles was 1.12 (after rounding) YPC above average in 2008, or 1.12 YPC above average on 5% of his career carries.
In ’09, Charles had 190 carries, representing 15% of his career YPC. He averaged 5.89 YPC, and the league average was 4.24, which means Charles was 1.65 YPC above average for 15% of his career carries.
In 2010, those numbers were 230, 18%, 6.38, and 4.21, so Charles was 2.17 YPC above league average on 18% of his career carries.
I performed that analysis for every season of Charles’ career — and every other player in NFL history — to determine each player’s career YPC average relative to league average. The table below shows the 200 running backs (by default, only the top 10 are shown) in pro football history with the most carries. The table is sorted by YPC over league average. Here’s how to read it. Jamaal Charles ranks 1st in YPC over league average. His first year was 2008 and his last year (so far) was 2014. For his career, Charles has 1,249 career rush attempts, which ranks 118th in pro football history. He has 6,856 yards, giving him a 5.49 career YPC average. His “expected” career yards per carry average — based on the league average YPC in each season of his career, weighted by his number of carries — is 4.21. Therefore, Charles has averaged 1.28 YPC above league average for his career, the highest rate in football history. [click to continue…]
On Friday, I asked the question: how many carries would we need to take away from DeMarco Murray in order to drop his YPC average to at or below league average?
Today, I want to look at it from the other side. How many of Trent Richardson’s worst carries would we need to erase to bring his YPC above league average? For this experiment, assume that we are sorting each running back’s carries in ascending order by yards gained. I’ll give you a moment to think about the answer.
[Final Jeopardy Music]
[Are you ready?]
[Your time is now up. Post your answer in the comments!] [click to continue…]
Suppose we sort each running back’s carries in descending order by yards gained. How many carries would we need to take away from Murray in order to drop his YPC average to at or below league average? Same question for Charles. I’ll give you a moment to think about this one.
[Final Jeopardy Music]
[Are you ready?]
[Your time is now up. Post your answer in the comments!]
[click to continue…]
Congrats to the newest members of the Pro Football Hall of Fame. You can read my thoughts on the candidates here; while this class is not exactly the one I would have picked, Jerome Bettis, Tim Brown, Charles Haley, Junior Seau, Will Shields, and Mick Tingelhoff were all outstanding players. In addition, Bill Polian and Ron Wolf were the inaugural selections for the Contributors spots, so congratulations to them as well.
The Bettis candidacy is an interesting one. Many want to focus on his underwhelming 3.9 career yards per carry average. But as I have written many times, I am not keen on putting much weight on YPC as a statistic. Brian Burke has also written about how coaches don’t view running backs in terms of yards per carry, but rather by success rate (which correlates poorly with yards per carry). Danny Tuccitto calls yards per carry essentially “a bunkum stat.” [click to continue…]
Last season, the Seahawks posted the best ANY/A differential in the NFL. In fact, it was the 9th best ANY/A differential of any team since the merger, and Seattle wound up becoming the 5th team in the top ten in that statistic to win the Super Bowl.
You heard all about Richard Sherman and Earl Thomas and the great Seahawks pass defense, and it’s not as though Russell Wilson was flying under the radar, either. But this year, the Seahawks are recording even more extreme statistics in a different differential stat.
Yards per carry is super overrated: Danny Tuccitto did a nice job revealing that just a couple of days ago. But hey, I love trivia, so let’s move on.
Seattle ranks 1st in the NFL in yards per carry (5.08). Marshawn Lynch is at 4.2 YPC on 132 carries, but it’s Wilson’s 7.6 yards per carry average on 52 carries that sets the Seahawks apart. But the defense — so unstoppable against the pass in 2013 — ranks 1st in this metric, too. Seattle is allowing just 3.19 yards per carry this year; if it holds, that would be the best mark since the 2010 Steelers.
Combine, though, is where the Seahawks really stand out. Seattle has a 1.89 YPC differential, defined as YPC for the offense minus YPC allowed for the defense. How good is that? If it holds, it would be the 2nd best mark since 1950: [click to continue…]
Regular readers know that I’m skeptical of using “yards per carry” to evaluate running backs. That’s because YPC is not very consistent from year to year. But it’s also not consistent even within the same year. For example, In 2013, Giovani Bernard rushed 92 times for 291 yards in even-numbered games last year, producing a weak 3.16 YPC average. But in odd-numbered games, Bernard averaged 5.18 YPC, rushing 78 times for 404 yards!
Jamaal Charles also showed a preference for odd-numbered games, averaging 5.80 YPC in games 1, 3, 5, etc., and only 3.96 YPC in even-numbered games. Buffalo’s C.J. Spiller had a reverse split, producing 5.57 YPC in even games and 3.61 YPC in odd games.
Okay, this stuff is meaningless, you say. Who cares about these random splits? Well, there are a couple of reasons to care. For starters, these splits serve as a great reminder that splits happen. If Spiller averaged 3.61 YPC in the first half of the year and 5.57 in the second half, the narrative would be that Spiller was finally healthy by the end of the year, and was set up for a monster 2014 campaign. Meanwhile, if Charles had seen his YPC fall from 5.8 YPC in the first eight games to 3.96 in the back eight, the narrative would be that he couldn’t handle a heavy workload, was breaking down, and could be a huge bust this year. Narratives are easy to invent, and remembering that “splits happen” is an important part of any analysis. [click to continue…]
The free agent running back market has been as peculiar as it’s been quiet. There have been no big contracts doled out and only a few sizable ones of note, although some of the ensuing narrative about the demise of the running back position has been overblown. Today I want to look at the ten biggest free running back signings1 of 2014 and see what conclusions we can draw.
Player contracts are notoriously complicated to analyze; I won’t pretend that we can truly and fully measure contracts handed out by ten different teams. But I won’t let the perfect be the enemy of the great: armed with the understanding that this analysis is not perfect, we march onwards. Over The Cap publishes detailed salary cap information, including the total value of the contract, the average per year, the amount of guaranteed money (which is never as clear as it sounds), the guaranteed money per year, the percent guaranteed, and the number of years. I’ve added one additional column: the approximate value of the contract in the first two years, which in itself is pretty tricky to calculate.2 It’s not close to perfect, but no method is, and I thought this was a better metric by which to sort the table than any other. Take a look: [click to continue…]
- Excluding Joique Bell, who was a restricted free agent. [↩]
- For players on one-year contracts, I averaged the guaranteed amount and the total amount, and multiplied that average by two. For players on two-year contracts, I averaged the guaranteed amount and total amount. For players on three- or four-year contracts, I treated the first two years as fully guaranteed and ignored the remainder. [↩]
How crazy is it for one back in a committee to average more than four more yards per carry than the other back? I ran the following query for every team since 1970:
- First, I noted the two running backs who recorded the most carries for each team
- Next, I eliminated all running back pairs where the lead back had over 150 more carries than the backup.
- I also eliminated all pairings where the lead back was a lead back in name only due to injury to the starter (otherwise, years where Maurice Jones-Drew and Darren McFadden ranked second on their team in carries would be inappropriately included). To do that, I deleted sets where the “lead” back — defined as the back with the most carries — averaged fewer carries per game than the second running back.
After running through those criteria, the table below shows all situations where the backup averaged at least one more yard per rush than the lead back. As always, the table is fully searchable and sortable. It is currently sorted by the difference between the YPC average of the backup and the starter, but you can sort by year to bring the recent instances to the top.
[click to continue…]
As you might expect, much of the blame falls on the Baltimore offensive line. In particular, tackles Michael Oher and Bryant McKinnie have been terrible, so much so that McKinnie was traded to Miami. Pro Football Focus also gives poor run-blocking grades to Ed Dickson, Dallas Clark (unsurprisingly), and Vonta Leach (very surprisingly). I haven’t watched enough of Baltimore to tell you why the Ravens have struggled so significantly to run the ball, but I can provide some perspective on how poorly Rice’s numbers are.
We don’t have play-by-play data going back to 1960, but we do have game-by-game data back that far. I went back and noted every running back who had a season-to-date yards per carry average below 2.80 following the game where he recorded his 97th carry. The table below shows the 43 players to do so from 1960 to 2012, sorted in reverse chronological order. The last player was former Raven Chester Taylor, and here is how his line reads: In 2010, playing for the Bears at age 31, Taylor had 105 carries for 252 yards, producing a 2.4 yards per carry average, following the game where he received his 97th carry of the year. The rest of the season, he had 7 rushes for 15 yards, a 2.14 YPC average.
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- How often does the first running back selected in the draft become the best running back from his class? The field is always a better bet than one player: Only about 40% of the highest-drafted backs led their class in rushing yards as a rookie, with that number dropping to about 33% on a career basis. On the other hand, that’s better than the production of the first-drafted wide receiver.
- In 2012, the field won, as both Doug Martin and Alfred Morris rushed for more yards than Richardson. I then tried to project the number of yards for all three players for 2013 based on their draft status and rookie production; as it turns out, draft status remained extremely important, and Richardson projected to average the most yards per game in year two out of that group (a projection that doesn’t look very good right now).
- In July, I continued to voice my disdain for the use of yards per carry as the main statistic for running backs, when I argued that Richardson’s 3.6 average last year was not important. More specifically, I said if you loved Richardson as a prospect, his 3.6 YPC average in 2012 was not a reason to downgrade him (of course, if you didn’t like Richardson, that’s a different story). Richardson still received a huge percentage of Cleveland carries and had a strong success rate, and I argued that his low YPC was simply a function of a lack of big plays. For a more in-depth breakdown of his rookie season, Brendan Leister compiled a good film-room breakdown of some of Richardson’s mistakes in 2012. Leister noted that Richardson had some mental mistakes, which isn’t atypical of a rookie, and still fawned over the former Alabama star’s physical potential.
- After the trade to Indianapolis, I wrote that Richardson’s ability as a pass blocker was tough to analyze, and advised you to view some of the numbers thrown around in support of Richardson with skepticism. Believe it or not, I still have thoughts on that trade that I just haven’t gotten around to finishing, so look for my hot take on the Richardson deal to be published in say, March.
In 75 carries with the Colts, Richardson is averaging just 3.0 yards per carry. Even though I find yards per carry overrated, there is a certain baseline level of production needed for every running back, and 3.0 falls well short of that number. For his career, Richardson now has 1,283 yards on 373 yards, a 3.44 YPC average. He’ll reach 400 career carries in a couple of weeks, so I thought it might be interesting to look at the YPC averages of all running backs after their first 400 carries.
We can’t measure that exactly through game logs, but what we can do is calculate the career YPC average of each running back after the game in which they hit 400 career carries. The table below shows that number for all running backs who entered the league in 1960 or later and is current through 2012. Let’s start with the top 50 running backs:
[click to continue…]
I’ve written a couple of times about “yards per carry” as a key statistic to grade running backs. The usual argument in favor of using YPC is that a running back who rushes for 1200 yards on 300 carries is less valuable, all else being equal, than one who rushes for 1200 yards on 250 carries. But when it comes to running backs and yards per carry, “all else” is is never equal. Two players come to mind whenever yards per carry is cited for running backs: Eddie George and Curtis Martin.
From 1996 to 2002, George led the league with 2,421 carries. Only Martin (2,236) was within 300 carries of George. In NFL history, Eric Dickerson is the only player to ever record more carries during a player’s first seven seasons. But some would have you believe that George wasn’t very good during those seven years, because he averaged just 3.71 yards per carry. During that stretch, the Titans went 68-44, giving them the fourth best record in the NFL and the second-best mark in the AFC during that span. But, the yards-per-carry proponents would argue, Jeff Fisher didn’t know what he was doing when he kept handing the ball off to George, play after play, game after game, year after year.
In 1998, the Jets went 12-4 and earned a first-round bye; New York went 12-1 in Vinny Testaverde’s thirteen starts, and finished in the top five of the league in points, yards, and first downs. That season, Curtis Martin received 369 carries despite missing one game due to injury. Martin rushed 25+ times in seven games and recorded at least 17 carries in every game that year… and averaged only 3.49 yards per carry. There are some who would have you believe that the Hall of Fame head coach didn’t quite know what he was doing that year, and the Jets would have been even better had the team called Martin’s number less frequently.
[click to continue…]
Last week, I wrote about why I was not concerned with Trent Richardson’s yards per carry average last season. I like using rushing yards because rush attempts themselves are indicators of quality, although it’s not like I think yards per carry is useless — just overrated. One problem with YPC is that it’s not very stable from year to year. In an article on regression to the mean, I highlighted how yards per carry was particularly vulnerable to this concept. Here’s that chart again — the blue line represents yards per carry in Year N, and the red line shows YPC in Year N+1. As you can see, there’s a significant pull towards the mean for all YPC averages.
I decided to take another stab at examining YPC averages today. I looked at all running backs since 1970 who recorded at least 50 carries for the same team in consecutive years. Using yards per carry in Year N as my input, I ran a regression to determine the best-fit estimate of yards per carry in Year N+1. The R^2 was just 0.11, and the best fit equation was:
2.61 + 0.34 * Year_N_YPC
So a player who averages 4.00 yards per carry in Year N should be expected to average 3.96 YPC in Year N+1, while a 5.00 YPC runner is only projected at 4.30 the following year.
What if we increase the minimums to 100 carries in both years? Nothing really changes: the R^2 remains at 0.11, and the best-fit formula becomes:
2.63 + 0.34 * Year_N_YPC
150 carries? The R^2 is 0.13, and the best-fit formula becomes:
2.54 + 0.37 * Year_N_YPC
200 carries? The R^2 stays at 0.13, and the best-fit formula becomes:
2.61 + 0.36 * Year_N_YPC
Even at a minimum of 250 carries in both years, little changes. The R^2 is still stuck on 0.13, and the best-fit formula is:
2.68 + 0.37 * Year_N_YPC
O.J. Simpson typifies some of the issues. It’s easy to think of him as a great running back, but starting in 1972, his YPC went from 4.3 to 6.0 to 4.2 to 5.5 to 5.2 to 4.4. Barry Sanders had a similar stretch from ’93 to ’98, bouncing around from 4.6 to 5.7 to 4.8 to 5.1 to 6.1 and then finally 4.3. Kevan Barlow averaged 5.1 YPC in 2003 and then 3.4 YPC in 2004, while Christian Okoye jumped from 3.3 to 4.6 from 1990 to 1991.Those are isolated examples, but that’s the point of running the regression. In general, yards per carry is not a very sticky metric. At least, it’s not nearly as sticky as you might think.
That was going to be the full post, but then I wondered how sticky other metrics are. What about our favorite basic measure of passing efficiency, Net Yards per Attempt? For purposes of this post, an Attempt is defined as either a pass attempt or a sack.
I looked at all quarterbacks since 1970 who recorded at least 100 Attempts for the same team in consecutive years. Using NY/A in Year N as my input, I ran a regression to determine the best-fit estimate of NY/A in Year N+1. The R^2 was 0.24, and the best fit equation was:
3.03 + 0.49 * Year_N_NY/A
This means that a quarterback who averages 6.00 Net Yards per Attempt in Year N should be expected to average 5.97 YPC in Year N+1, while a 7.00 NY/A QB is projected at 6.45 in Year N+1.
What if we increase the minimums to 200 attempts in both years? It has a minor effect, bringing the R^2 up to 0.27, and producing the following equation:
2.94 + 0.51 * Year_N_NY/A
300 Attempts? The R^2 becomes 0.28, and the best-fit formula is now:
2.94 + 0.53 * Year_N_NY/A
400 Attempts? An R^2 of 0.26 and a best-fit formula of:
3.18 + 0.50 * Year_N_NY/A
After that, the sample size becomes too small, but the takeaway is pretty clear: for every additional yard a quarterback produces in Year N, he should be expected to produce another half-yard in NY/A the following year.
So does this mean NY/A is sticky and YPC is not? I’m not so sure what to make of the results here. I have some more thoughts, but first, please leave your ideas and takeaways in the comments.
- His 3.6 YPC average came on 267 carries, which represented 77% of all carries by Cleveland running backs
- He was a rookie last year
- He was a high first round pick
Since 1970, only 13 first round rookies have recorded 70% of all running back carries by their team. Two of those players were Richardson and Tampa Bay’s Doug Martin last year. Of that group, Richardson did post the lowest YPC average, but he was within 0.1 YPC of LaDainian Tomlinson. The next two lowest averages belong to Robert Edwards and Emmitt Smith; the former suffered a career-debilitating injury in a beach football game after his rookie season, while the latter ran for the most yards in NFL history.
Yeah, Richardson’s yards per carry average was well below average. But the universe of first round running backs who became workhorses right away as rookies and had a low YPC average consists of a HOF running back, a future HOF running back, and a player who suffered the flukiest of injuries. Richardson has something else in common with Emmitt Smith: after both of their rookie seasons, Norv Turner came on board as offensive coordinator.
But let’s say you don’t want to give Richardson any credit for his draft status. And you’re not in the mood to give him a pass just because he was a rookie. OK. Since 1990, 48 running backs have averaged fewer than 3.8 yards per carry while recording at least 70% of all running back carries for their team. Twenty-six of those players were at least 27 years old, and on the back half of their careers. Here are the other 22 running backs:
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Carolina’s Cam Newton led the league in yards per carry in 2011, which isn’t that unusual. Michael Vick led the league in that category in five of the last ten seasons, and it wouldn’t be shocking to see Robert Griffin III, Newton, or Vick lead the NFL in yards per carry in 2012. But today’s trivia is focused on running backs.
Darren Sproles not only led the Saints in rushing yards, but he averaged an incredible 6.9 yards per carry last season. Sproles may be the game’s most dominant space player, but he fell 13 carries shy of the 100 carries necessary to qualify for the yards-per-carry crown. So which qualifying running back led the league in yards per carry in 2011?