Latest NFL Moves: Jonathan Williams, Matt Jones, Jeremy Langford, and Alex Collins

No offensive position carries more fantasy volatility than running back. Collectively, RBs offer the most surprising upside and the most painful downside. We roster them because we need to. We keep them because they're healthy and producing. We replace them when they, themselves, have been replaced.

If I could have 15 bench spots, at least 10 would be RB handcuffs. But yesterday's NFL news reminds us that some of it is a guessing game. One day you're holding a sure-fire handcuff; the next day he's unemployed.

It starts with Jonathan Williams, who for months has been LeSean McCoy's assumed handcuff. Then the Bills shockingly waived him on Sunday, making the 31-year-old Mike Tolbert the new handcuff, with no one behind him capable of seriously challenging anyone. I suspect there's more to this Williams story, as talent-wise his departure makes the team markedly worse. That said, don't rush out to add Tolbert. Another handcuff will likely emerge; plenty of better candidates are floating around the league these days.

Matt Jones was one of them, before the Colts snatched him up. If the 24-year-old can fix his fumbling problem, he'll be a high-impact RB if he ever gets the chance. Marlon Mack and Robert Turbin take hits. In the next 2-3 weeks we'll know who the true backup is here, and it mostly hinges on Jones proving he can hold onto the ball.

Jeremy Langford entered last season as Chicago's bell-cow. Now he's looking for work, as yesterday the Bears cut him. Benny Cunningham and Tarik Cohen were already expected to support Jordan Howard when needed; now it's an even clearer picture. Wherever Langford lands, ignore him.

Finally, last preseason Alex Collins looked like a candidates for early-season touches in Seattle. Sunday he was let go, leading him to join the Ravens' practice squad. It will take only an injury to one of Baltimore's three main contributors--Danny Woodhead, Terrance West, or Buck Allen--to give Collins another opportunity. It will take two injuries to make him fantasy relevant.

No other position plays musical chairs like RBs. Sometimes a different offensive scheme, offensive line, coaching style, or set of teammates could impact how a running back fares in one place vs. another. Plenty of franchises are hoping to strike gold where others struck bronze. As fantasy managers, we're doing the same.