It's Week 18, and with the playoff picture taking shape, NFL DFS contests are brimming with opportunity. Running back is always a key position, and this week we have several enticing matchups at various price points. Whether you're building around high-priced workhorses or searching for value to balance your lineups, this slate has something for everyone.FanDuel's scoring system rewards touchdown-heavy backs, while DraftKings gives extra value to pass-catching RBs. I've highlighted four top ...