Rivals.com national college football writer Olin Buchanan has been a Heisman Trophy voter for 15 years. Here is his preseason top five Heisman contenders and a brief case for why each could win. We would like your opinion, too. Cast your votes and let us know if you think Olin is right on, or if he is off the mark.

					Case Keenum,#7 QB, Houston, Junior. Keenum leads the nation with 3,293 passing yards, which is 616 yards more than anyone else. Twice this season, he has exceeded 500 passing yards. Four times, he has thrown for more than 400 yards.
					Jimmy Clausen,#7 QB, Notre Dame, Junior. Clausen completed more than 80 percent of his attempts for 268 yards and two touchdowns in last week’s rout of Washington State. He has thrown for at least 246 yards and two touchdowns in seven of eight games. The one in which he didn’t, he came off the bench to lead the Irish to the game-winning touchdown against Purdue.
					Mark Ingram,#22 RB, Alabama, Sophomore. Last week’s leader shouldn’t fall just because his team was idle. Ingram has rushed for 1,004 yards and eight touchdowns. That includes 657 yards in the past four games. He could really bolster his campaign with a big game against LSU on Saturday.
					LaMichael James,#21 RB, Oregon, Freshman. James, a redshirt freshman, has rushed for 918 yards, but keep in mind that he played sparingly in the Ducks’ first two games. Since then, he has exceeded 100 yards in five of six games and is coming off a career-best 183-yards outburst against USC.
					Jacquizz Rodgers,#1 RB, Oregon State, Sophomore. There may not be a more versatile player in college football. He has rushed for 922 yards and 14 touchdowns and hasn’t been held to fewer than 73 yards in a game this season. He also has 49 receptions for another 371 yards. No other running back has more receptions. He’s also tied for second in the nation with 90 points.