You do not need any advanced statistical analysis to figure out why John Beck remains the Redskins' starting quarterback even though the team has not won a game with him under center. Rex Grossman has led the team to three wins this year, but dont look for him to be playing with the first team any time soon.Beck has one important advantage over Grossman that virtually guarantees, barring disaster, he will be starting for the rest of the season.What is Becks big advantage?His contract.Soon after Beck was traded from the Ravens to the Redskins in August 2010, he signed a three-year contract extension. He is signed through the 2012 season.When Grossman came to the Redskins in 2010, he signed a one-year contract. After the lockout ended this year, he signed another one-year deal. He hinted he could have signed for longer but he decided he would rather have the ability to negotiate a new deal in 2012.That would have allowed Grossman to cash in if he could have a solid 2011 season. Things were looking good when the Redskins started 3-1 and Grossman was making plays and moving the team. But then came the four-interception game against the Eagles and his subsequent move to the bench.And he is likely to remain on the bench for the rest of the season, at least in part because even if he overcomes his turnover-prone ways, the Redskins may not be the team that benefits from his improvement. When the league year starts next March, Rex will be able to sign anywhere he wants to.Availability next year is particularly important because the Redskins are likely to draft a quarterback in April. They will need a transitional QB who can start the season and who will be able to take over from time to time if the rookie struggles. If Grossman is gone, he cant be that guy.But Beck remains under the Redskins control through the transitional 2012 season. He could be that bridge quarterback if he can develop into a marginally competent NFL QB.If Beck is unable to up his game, the Redskins will have to bring in a veteran quarterback from another team next spring. The teams time and attention will have to be focused on teaching two different players the offense rather than just one.The ideal situation would be to have a guy who knows the offense and can run it while the rookie learns. Beck has a chance to be that guy.The Redskins will spend the rest of this year giving Beck that chance because they know they can keep him here next year. If they spend the time on Grossman, there is no assurance he will be back next year.Yes, it a sad state of affairs when the last half of an NFL season has to be spent developing a temporary solution to what has been a long-term problem for the Redskins. Time will tell if Mike Shanahan erred in not drafting Blaine Gabbert or Christian Ponder or another quarterback last April.Regardless, the draft cant be redone. Sometimes, availability is just as important as ability. The best option now is to give playing time to the quarterback they know will be around next year.