When you have two quarterbacks, you don't have one.

We know that saying.

It's true, and it applies to other aspects of football -- including the fantasy angle.

When a backfield has two -- or three -- backs, it sure doesn't have one who is the guy.

That's the situation in the Buffalo Bills' backfield, which features last year's primary back (Devin Singletary), a second-round rookie with elite pass-catching upside (James Cook), and a likely trade candidate (Zack Moss).

It's quite clear that it's more of a two-man race than a three-headed committee with Singletary (the RB32 in FanDuel's best-ball average draft position) laying claim to the early-down work and Cook (the RB34 in ADP) holding a third-down role.

When projecting out this team from a median standpoint, it's hard to disagree with how our fantasy football projection model projects them.

In half-PPR setups, Singletary is ranked as our RB29 on the strength of a 173-carry, 786-yard, 4.7-touchdown rushing line and a 50-target, 230-yard, 2.3-touchdown receiving campaign.

As for Cook, he's the RB43 with a projected line of 111 carries, 28 targets, 558 scrimmage yards, and 4.5 total touchdowns.

With both healthy, they're likely each low-end RB2s or high-end RB3s with Cook generating a substantial boost in full-PPR leagues. Even those roles have value while tied to one of the NFL's best offenses.

But if things go right for one of them, then we're going to hope we have some shares.

Devin Singletary's 2021 Season

So, the thing of it is: the Bills hadn't really supported a viable fantasy football running back in recent seasons -- until last year when they finally turned things over to Singletary. Of course, the results weren't immediate.

Singletary played 73.4% and 65.6% of the team's snaps in the first two weeks of the season and then didn't break the 50.0% barrier again until Week 9 when he got to 70.8% of the snaps.

Through Week 9, Singletary was the RB40 in half-PPR formats.

From there, he played 38.9%, 37.0%, 67.7%, and 47.4% of the team's snaps through Week 13.

And then things changed.

Singletary, from that point on, had a low-water mark of 70.7% in the snap rate column and then ultimately played every offensive snap in their AFC Divisional Round game against the Kansas City Chiefs.

From Week 14 onward, Singletary was the RB4 (including playoffs) in half-PPR points per game (18.2).

If we look only at games in which Singletary played at least 50.0% of offensive snaps, then he (15.3 points per game) would've been good enough for the RB10 in 2021 on a per-game basis.

Am I projecting or suggesting that Singletary will have a 50.0%-plus snap rate weekly or that his role won't scale back with Cook taking passing-game work? Nope.

But if and when a back actually has been featured in this backfield, the results have been much more promising than an RB32 or RB34 ADP.

The ceiling for these guys is being featured in an elite offense. If accounting for floor or most-likely-outcome, then, yes, these guys are going to be ZeroRB candidates in the middle of the draft.

How likely is it that Singletary churns out a majority role?

How Much Work Can James Cook Handle?

One of the biggest question marks with Cook's profile coming out of college this year was his workload.

Cook ranked in the third-percentile in max rushing share in my draft model. To be fair, he was still in the 43rd-percentile in receiving share despite being a part-time player in college. Though this alone doesn't preclude him from handling carries in the NFL, it's fairly safe to assume that the majority of the rushing work will belong to Singletary.

Also, Cook is 5'11" and 190 pounds, and smaller backs tend to get hurt at a higher rate than bigger backs, so while Singletary is going to relinquish some pass-catching work, his target share was only 8.7% this past season, and in those games while featured, it got bumped to 10.7%.

That's certainly not nothing, but a 53.3% red zone rushing share and efficient rushing within an offense where nobody is game-planning to stop Singletary is what really got him over the hump.

The Takeaway

By drafting either Singletary or Cook, you're buying into what is -- for now -- a committee with the high-leverage work split. Red zone work should belong to the bigger Singletary; Cook should steal valuable targets.

So, again, their status as low-end RB2s or high-end RB3s is pretty cemented, given the offense in which they play. In this sense, you have to be projecting the Bills' offense to take a large step back for them both to bust hard at those ADPs and be totally irrelevant on a weekly basis.

While that'd be a bummer, you're already well past the territory of surefire picks once we get to the RB30 range in drafts.

The alternative to that scenario of a true enough workload split or a massive regressive season for the offense is that the backfield takes on some sort of featured player.

That could be Singletary carving out a 70.0% snap rate with a few targets but a big portion of the high-leverage goal-line carries.

That could also be Cook proving capable of handling one of the NFL's highest target shares among running backs while also showing enough on the ground to be a low-volume-but-still-three-down back.

History says that matters.

Since 2012, among 120 top-12 running back seasons, 65.8% of them came from teams ranked 16th or better in numberFire's offensive efficiency metrics. There's a ton of room for Buffalo to drop back and remain in the top half of the league from an efficiency standpoint.

And if they stay elite, even better: 42.5% of top-12 backs played on a top-10 offense in this sample. That's a great sign for the potential upside for Singletary and Cook.

Right now, given their average draft positions, we're buying in at their likely floors, and it's very possible that one of them gets stints throughout the season as the guy in the backfield for one of the NFL's best offenses.

I'll gladly target these Buffalo backs over other committee backs at similar ADPs in hopes of a ceiling season that others on bad offenses likely can't offer.