Week 17 of the NFL includes a matchup between the Buffalo Bills and Miami Dolphins. In this must-win battle for Buffalo, the Bills are favored by three points, up half-a-point after opening as 2.5-point favorites. The over-under, or total number of points Vegas thinks will be scored, is 42.5, down half-a-point after opening at 43.

Before you make any kind of bet on this game, you need to see what elite NFL handicapper R.J. White has to say.

White has absolutely crushed his picks this season, becoming SportsLine's most profitable NFL expert by returning almost $2,000 on $100 bets this season. And now he's in the top 1 percent of the Las Vegas SuperContest, one of the world's most prestigious sports handicapping tournaments -- a contest in which he has previously finished in the top 2 percent.

Amazingly, out of 2,748 entrants, White is tied for 21st this year. Anybody following his picks has been getting advice from one of the top experts in the industry and is up huge on their selections.

White has analyzed every angle of this showdown between the Bills and Dolphins and jumped all over one side. He's sharing that pick over at SportsLine.

White knows that the Bills must win this game to have any shot at the postseason. Even with a victory, Buffalo still needs help, but there is no path to the playoffs without a victory over the Dolphins first.

That means the Bills have a huge motivational edge. The Dolphins are done after a Week 16 loss to the Chiefs, leaving them with nothing to play for except possibly sending Jay Cutler back to the broadcasting booth with a win.

But just because there's a motivational edge for Buffalo doesn't mean the Bills will cover the full three-point spread.

The Dolphins have shown they can play with anybody this season, as evidenced by their shocking 27-20 win over the Patriots in Week 14. And the Bills generally don't blow teams out. Instead they use a tough defense and a solid run game to keep games competitive. Their past three wins have all come by just one score.

White is leaning under, but he knows there's a huge x-factor that determines which side of the Bills-Dolphins spread you need to be all over. And Galin Dragiev, who's on a 19-9 NFL run, agrees with him.

So which side of Bills-Dolphins should you jump all over, and what is the x-factor that White believes will be the difference in this matchup? Visit SportsLine now to see which side of Bills-Dolphins White is backing, and what the x-factor will be on Sunday, all from the expert who is in the top one percent of one of the world's most prestigious handicapping contests