It’s been a particularly soft market for running backs, and the top one on our list, Michael Bush, finally found a home: the Bears announced they reached a four-year deal with Bush on Thursday.The deal is worth $14 million. Frankly, that’s a steal, even if it’s for a guy who will now serve as the backup for Matt Forte, who was given the franchise tag this offseason.In four years with the Raiders, Bush has carried the ball 632 times for 2,642 yards, 21 touchdowns and a 4.1 YPC average. He also has 91 catches for 879 yards in that span.It’s a very nice signing for the Bears, whose running game struggled in 2011 after Forte went out with an injury. In fact, backup Marion Barber (who is likely to get cut) created one of the more “memorable” NFL moments of last season when he ran out of bounds during regulation and fumbled in overtime to let the Broncos steal a win over the Bears during the height of Tebowmania.Additionally, Forte wants to get paid, and Bush provides very nice, non-aggressive leverage when the Bears start talking with him about a longer contract. If Forte refuses to take a big paycut, the Bears could even conceivably let him walk after the franchise year and allow Bush to take over as the full-time back. Forte obviously sees the Bush signing as the Bears not-so-subtley addressing his contract status, or else he wouldn’t have tweeted … this: