From the FanPosts. Excellent post. -Joel

Here’s why I’d start Jamaal Charles at running back if I were building a team from scratch.

The idea for this post originated months ago with a mistaken assumption on my part. Specifically, I wrote in a comment thread that Frank Gore was obviously a better short yardage runner than Jamaal Charles. MNChiefsFan challenged me to back up my statement, and when I did the research, I found that Charles is far and away the better running back with fewer than 2 yards to go. In fact, Charles compared favorably to any other big time running backs that I examined at the time. Who knew?

When I realized that Charles' strengths included more than yards-per-carry efficiency and a dangerous ability to take it to the house, I decided to figure out where JC fits in the ranks of current NFL running backs. The off-season "Top X" lists further inspired me, especially b/c Pro Football Focus somehow found 7 running backs who turned in better seasons last year than Jamaal Charles. I couldn't buy it, even after reading their follow-up post that tried to justify their choices.

Everything that follows is an attempt to answer a simple question: "if I were building a team from scratch, which running back would I most want on my roster?" The answer is, of course, Jamaal Charles. He didn't actually emerge as the top-rated RB in this study, but for my money JC offers the best combination of youth, experience, durability, situational effectiveness, and bulk production. I think, too, that you might be surprised by how some of the other top backs fared in this study.

Methodology:

I used the ‘Player Season Finder' at Pro Football Reference (PFR) to identify the most productive "feature backs" in the league today. My criteria were as follows:

• For players active in 2009, I required the RB to have at least 400 carries and 40 receptions.
• For 2010 players, I chose C.J. Spiller and Ryan Mathews as the only credible "feature backs" of that class.
• For 2011 players, I likewise chose only DeMarco Murray to add to my list. (with apologies to Stevan Ridley. I should have included him here. My bad.)
• In 2012, we saw three RBs join the cadre of top flight runners: Alfred Morris, Doug Martin, and Trent Richardson.

These queries yielded 43 names, and I ranked them from 1 to 43 in each of 9 areas under study (where the guy with the best numbers got a ‘1'). I derived my final ranking by taking the average of the 9 scores. This means I weighted every category equally, which is an entirely debatable proposition, but it was all my poor mind could handle.

I collected the data from three broad perspectives:

• Bulk production - These metrics include carries, receptions, yards, touchdowns, etc., and serve as a basic expression of overall productivity.
• Situational effectiveness - These metrics report how well the player performed in common down-and-distance situations: ‘goal line success', ‘red zone success', ‘short yardage success', and ‘first-and-10 efficacy'.
• Comparative production - These metrics add utilization information to convey a rate of productivity: ‘yards per carry', ‘yards per catch', ‘total yards per game' (excluding kick returns), ‘touchdowns per game', and ‘reception rate'. They let us compare the efficiency of the RBs under scrutiny.

I'm only going to write about the last two data sets, because the raw metrics don't tell us anything more than what is obvious - Adrian Peterson is a stud, and Doug Martin might just be his under-stud-y (get it?). The charts should have a minimum of explanation and commentary b/c I really want to read the thoughts, arguments, and conclusions that the rest of AP comes up with. You guys and gals never disappoint in that regard.

The Running Backs

I wanted to identify the ideal ‘feature back' for years 2013 and beyond, so I didn't include data for retired or clearly past their prime RBs (e.g., LaDainian Tomlinson, Michael Turner, etc.). I also ruled out RBs who are not now and will likely never again be used in a feature role, e.g., Michael Bush, Marion Barber, etc. Finally, I ended up throwing out Trent Richardson as well b/c his 2012 productivity just wasn't up to the standards set by the rest of the group. This process left me 21 names, shown here with some interesting data about availability and utilization.

There's an important fact to bear in mind as you read these charts: even though I show rankings from 1-21, I still used the larger pool of data to derive my overall average. I did so because I believe that it better separates the players to consider where they rank among the more complete group of their peers. A pair of RBs might rank 5-6 in the abbreviated list when they rank 11 and 18 in the full group - a much larger distinction than might otherwise be indicated.

This first chart is the "money shot", the one that summarizes my findings.

Notes:

Games Played is the number of games played over the sample period (as opposed to career games played).
Availability is the proportion of games in which the RB played in the period under study. For Jamaal Charles this is 49 of a possible 64 games (I didn't include the Detroit game where he got injured on the second play from scrimmage).
Utilization is the proportion of offensive plays in which the RB tallied a running attempt or was a targeted receiver (even if the pass is incomplete, the offense still used the player in that instance).
CP Rank shows how a player ranked in the "comparative production" part of the study.
SE Rank shows how a player ranked in "situational effectiveness".

Jamaal Charles ranks fourth in utilization at 37.37%. This would seem to refute the claim, one that I still read from time to time, that Charles has not been used enough in the Chiefs' offense. His availability has been 76.56%, or 19th of 21 players. To me, this needn't reflect poorly on Charles. All of his time missed came in 2011 as a result of his ACL injury, and he hasn't missed any games due to nagging injuries. In this respect, JC is quite durable, especially considering his workload.

Comparative Production Metrics

These are the metrics that allow us to compare the RBs' play-to-play and game-to-game productivity.

Jamaal Charles is 7th on this list. His production in the passing game pulls him down, and he hasn’t scored a lot of touchdowns. I can’t wait to see whether the new coach and QB will help his standing here.

Situational Effectiveness

This is where Jamaal’s skills really shine.

First Down and Ten Yards To Go

On average, just over half of the carries for a first-team running back occur on first-and-10. Success in this situation, which I have defined as a gain of 4 yards or more, allows the team to open up the playbook on 2d and 3d downs, leading to big play opportunities. On the other hand, failure (0 to negative yards) leads to 3rd and long all too often.

Jamaal Charles is not only tops in success rate here, but he also has the 5th lowest failure rate. Meanwhile, if you want to see how Marshawn Lynch, Ray Rice, Frank Gore, and Adrian Peterson rate – four reputedly stronger runners – you’ll have to peruse the bottom half of the list.

Short Yardage

Many football sites define a short yardage situation as a play where at most 3 yards are needed to get a 1st down. I set the limit at 2 yards for my study. Success, obviously, requires the RB to gain at least the 2 yards needed for a new set of downs.

With 2 yards to go, you know the defensive front 7 is geared up for a running play, especially when it involves the Chiefs. No matter how good the blocking may be, the only way JC achieves this stellar rate is to have the vision, quickness, balance and footwork to avoid defensive penetration into the backfield.

Red Zone Success Rate

I set a pretty high standard for success in the red zone (the area inside the opponent’s 20 yard line): the RB must either score a touchdown or gain a first down, and a touchdown is worth 1.5 times as much as a first down. The rankings below result from adding the two metrics, where SuccessRate = TD%*1.5 + 1stD%.

Jamaal’s numbers are just OK in this situation. Even so, if there is one area where JC hasn’t been used enough, it’s this one. His 59 carries represent only 17% of the red zone plays run by the Chiefs in games he played.

From Inside the Opponent’s 5 Yard Line

The only result worth considering is a touchdown, so this table is pretty simple.

Jamaal Charles comes through again! The sample size is quite small, which mostly reflects how few plays the Chiefs ran in this part of the field over the last 4 years. Will he maintain this success rate as the offense becomes more successful? I can only hope we get to find out.

Wrapping It Up

Congratulations and many thanks if you've read this far! Even though the post is a bit data-heavy, I hope it proves interesting enough to spur some fun discussions as we wait for training camp to start.

This research germinated a large number of sidebar notes, and I’ll post one or more follow-ups in a few days to delve into some them. Here’s a preview:

1. Pro Football Focus can suck it. They have clearly abused their own advanced stats, and I’d like to illustrate just how far off the rails they have gone.
2. Contrary to the current consensus, the running back is more important than ever to a well-functioning offense.
3. Does Ahmad Bradshaw really belong at #4? And what about Marshawn Lynch at #17? I’d like to take a closer look at some of the more surprising results.
4. Speaking of Marshawn Lynch, I suspect that playing alongside a running quarterback makes a running back more effective than he’d be in a more ‘traditional’ offense. Is it possible or fair to identify and adjust for this effect?
5. We love football not because of the stats, but because of the real-time action. How about some GIFs to demonstrate what the numbers seem to tell us?