Note: This article assumes PPR scoring. It is, in part, a follow-up to this piece analyzing fantasy football running backs by Actual Opportunity (expected fantasy points) and this article, debating the merits of a Zero-RB strategy for the 2018 fantasy season.
The running back position has become the most hotly debated position in fantasy football, with a multitude of theories on what your best approach is, and it’s become that way for good reason.
Running backs touch the ball and are tackled more often than any other flex position, and as a result offer more upside than any other position (and also more injury risk). Over the past 15 fantasy seasons, in PPR scoring, nine of the 10 highest-scoring non-quarterback seasons (90 percent) came from running backs. Same for 15 of the top 20 (75 percent), 23 of the top 30 (77 percent), and 38 of the top 55 (69 percent). Two seasons ago, Le’Veon Bell outscored the nearest wide receiver (Antonio Brown) by 5.6 fantasy points per game. Last season, Todd Gurley outscored the nearest wide receiver (Brown) by 3.7 fantasy points per game.
The flip side is that value drops off quickly – and it continues to depreciate by the number of wide receivers or flex players you start. Over the past decade, on average, the top 48 flex players typically comprise 17.8 running backs, 4.4 tight ends, and 25.8 wide receivers.
All that is a long way to explain why I’m Team Bell Cow or Bust.
I want running backs who rank highly in snaps, carries, and targets. But that’s not all. I also want them to rank highly in percentage of team running back snaps, carries, and targets, to ensure they’re gamescript-proof. Being game-script-proof is important. In 2015, Danny Woodhead and Doug Martin finished top-five in total fantasy points, but both were maddening to own. Woodhead finished outside of the top-24 running backs in 44 percent of his games, Martin in 38 percent. That's not helpful. I’ll treat early-down workhorses and pass-catching running backs the same way – I don’t go out of my way to acquire them. They’re easily replaceable and not very valuable.
The running back position is the most volume-dependent position in fantasy, and as a result efficiency matters less so than for other positions. Over the past 10 seasons, raw snaps had a 0.88 correlation to fantasy points for running backs, but that number is just 0.83 for wide receivers and 0.77 for tight ends.
For years, I’ve tried to measure what it means to be a “bell cow” running back. This season I’ve settled on my preferred approach. My Actual Opportunity metric calculates a player’s expected fantasy points based on a 10-season sample of what the league average player would have scored on an identical workload. This is the most effective metric I’ve found at calculating the worth of a player’s role. Looking only at games a running back was active, we can divide a running back’s Actual Opportunity score by the team’s total Actual Opportunity score at the position to measure their stronghold over the backfield. This measurement – AORB% — will serve to measure how much of a bell cow a running back was. The below chart lists the top-15 running backs by AORB% and also offers their snap, carry, and target market share at their position.