I think if you search the archives, you can find previous articles that I've written about how important it is where a player's opportunities occur. But as statistical analysis tools proliferate on the Internet, particularly PFR's Play Index and RotoViz's Screener App, I feel like I need to dig deeper into this topic. I'm know other analysts on other sites have covered some of this ground (kudos to them[i]), but I wanted to do my own work and maybe add to their work. Today I'll start with running backs. For now, I will only describe what occurs when an RB gets a hand-off or a pass thrown to him but I hope eventually to use this to analyze future performance and make predictions.

Using "The RotoViz Screener," I looked at all running back carries and targets since 2002 (the 32-team era) to see how many fantasy points each carry and each target generated (10 yards = 1 FP, TD = 6 FP, and 1 FP/reception scoring). Overall, an average carry by an RB scores 0.59 FP and a target nets him 1.44 FP on average. In PPR systems, an RB target is worth almost two and a half times as many fantasy points as a carry.

But that greatly underestimates the value of some opportunities as this chart shows:

FP per RB Opportunity, 2002-2015

 

  Opp Yd Line
 Type

1 to 5

5 to 10

10 to 20

Outside 20

 
 

Rush

2.39

0.92

0.59

0.48

 

Target

3.01

2.14

1.58

1.37

 


A carry or rush at the goal-line, that is, between the opponent's 1 and 5 yard-line, averages 2.39 FP because a TD is so much more likely. But if the line of scrimmage is back one 5-yard increment, from the opponent's 6 yard-line to his 10, an RB averages only 0.92 FP per attempt. And outside the red zone, the typical RB carry is worth less than half a fantasy point: a goal-line carry is worth about five times the fantasy points of a non-red zone run.

At every distance increment in the table, a target is worth more than a rush. Inside the 5, a target is only about 25% more valuable but after that it quickly generates more than twice as many points as a run, up to almost three times as many outside the 20. An average non-red zone target scores more FP than any carry except one inside the five (the four yard-line, actually, as we'll see in a minute).

The chart actually understates the value of close-in rushes and targets. For example, while the average carry inside the 5 is worth 2.39 FP, RBs actually average 3.27 FP on carries from the opponent’s 1 yard-line. This graph shows how scoring averages drop off rapidly as the line of scrimmage moves within the red zone:

There are some strange bumps in the graphs, which just may be data anomalies or may have something to do with play-calling and defensive alignments. For example, FP/Target goes up noticeably from the 1 to the 2 yard-line, the 5 to the 6, and 12 to the 13. FP/Rush is very level from the 9 to the 17, then drops to a new level from the 17 to the 18 (and basically continues at that level for the rest of the field). My speculation is that the drop in FP scoring on runs at that point has something to do with the distance the safeties are from the line of scrimmage and their closing speed, but it would take a lot of detailed study to figure that out.

RB points per carry level out at around the 20 as the graph indicates. But their FP/target actually don’t reach the "rest of the field level" until about the 25 yard-line. Targets between the opponent's 20 and 25 yard-line are worth about 5% more for fantasy than those beyond the 25.

Notice from the graph that the average carry from the 5-yardline scores 1.32 FP – less than the value of an outside the 20 target.

I don't think it's any surprise to experienced fantasy players that goal-line carries are worth a premium or that RBs with a passing game role are more valuable than ball-carriers who rarely catch a pass. At this point, I'm just trying to quantify those values. With further work, I hope to turn that information into something that will be more useful. I'll leave you with this table to ponder:

FP for Different RBs

RB Type

Rushes

Targets

FP

A

240

20

170

B

150

60

175

C

100

70

160

D

40

80

139

The FP column is based on an average distribution of carries and targets across the field – a back with a higher than typical number of goalline or red zone opportunities would score more. Last year, RB "A" looked like Jonathan Stewart or Jeremy Hill. RB "B" would have been Giovani Bernhard, "C" was Charles Sims or Duke Johnson, and "D" was approximately Theo Riddick. Because RBs get more carries than targets, a Type A is still worth more than a Type D. But I'm pretty sure you want a Type B or C over and A when all three are playing as underdogs and more likely to throw, and a Type A when their teams are heavy favorites.

 

[i] RotoViz in particular has calculated expected points for every carry and target depending on field position as well as down and distance. I've also down some preliminary work on game situation (score, time remaining) that shows that those factors matter too. For example some of my work with the PFR Play Index for 2015 shows that a run on 1st and 10 in the first half of a game with the score within 7 points averaged 4.3 yards but a carry on the same down and distance in the 4th quarter of a game within 7 points only gained 3.8 yards. I'm ignoring down, distance, and game situation entirely in this article.