The college football season starts in less than a month, and bold predictions are rolling out. Just don’t believe everything you hear, especially when it comes to the Heisman Trophy. Making picks about the sport’s preeminent award is as difficult as ever.

The Heisman is always a standard futures bet before the season kicks off. But in the past decade, according to Sports Odds History, only one of the 10 players favored to win the award entering Week 1 has hoisted the trophy in December: Oregon’s Marcus Mariota in 2014, who was a slim favorite after leapfrogging returning winner Jameis Winston of Florida State in the offseason. If we add up their implied probabilities, the past 10 favorites should have produced 2.14 winners. But a $10 bet on each of the 10 would have cost $100 and paid out just $42.50, on Mariota.

In fact, of the past 10 winners, four started the season off the board — Alabama’s Mark Ingram in 2009, Auburn’s Cam Newton in 2010, Texas A&M’s Johnny Manziel in 2012 and Winston in 2013 — as did 15 of 40 finalists. That’s because college football is filled with unexpected breakout stars. Especially as the top performers have been younger recently, predicting which candidates will live up to the hype is a tough task.

On paper, the Heisman winner seems like a reasonable thing to handicap as the winners tend to fit a longstanding mold. Almost all are quarterbacks or running backs, and most will be competing in the national title picture late in the fall. If the teams favored to compete for the title this season hold up, that would seem to whittle the Heisman field to a pair of easy choices: Alabama’s Tua Tagovailoa and Clemson’s Trevor Lawrence. Neither is mired in a quarterback competition this summer, and both were brilliant for much of last season. They’re co-favorites at 11-4 odds, according to the Westgate Superbook. In the past 10 years, only Tim Tebow (9-4) in 2009 was a bigger preseason favorite.

But change comes quickly in college football. One year ago, neither Tagovailoa nor Lawrence was even certain to start his team’s season opener. Tagovailoa spent much of the fall as the Heisman front-runner until he went down with an ankle injury and Kyler Murray surpassed him for the Heisman. Lawrence ended the season as the spectacle of the national championship game. But now Tagovailoa is healthy again and coming off a season in which he had better overall numbers than Lawrence. Would you bet money on one of the two weathering another long season to prevail as the country’s most outstanding player? And even if you would, which one?

Of the top five Heisman contenders according to Westgate, three — Lawrence, Oklahoma’s Jalen Hurts and Ohio State’s Justin Fields — are in their first full year as the starting quarterback on their current team. Two of the five are transfers, and only Tagovailoa has been a finalist before. Then contend with the fact that five of the past 10 winners started with odds of 100-1 or longer, which opens the door to the likes of Arizona’s Khalil Tate, Washington State’s Gage Gubrud and Florida’s Feleipe Franks. If they seem obscure, just remember Manziel in the summer of 2012.

That 2012 race was perhaps the wildest in recent memory, complete with the awarding of a “September Heisman.” Through five weeks, West Virginia quarterback Geno Smith was unstoppable, it seemed — a 1-1 favorite. In his first five games, Smith completed 81.4 percent of his passes with 399.2 yards per game, 24 touchdowns and zero interceptions. But in his last eight games, he completed just 64.6 percent of his passes with 18 touchdowns and six interceptions. Manziel, meanwhile, went from off the board to 7-4 in five weeks. If that sounds quick, this is Lawrence’s 2018 in comparison: He was a 40-1 contender entering Week 1 despite the fact that he wasn’t the starter until Week 5. Then Lawrence threw more touchdowns and fewer interceptions in his last five games than Manziel did in the last five of his redshirt freshman season.

The odds are not a science, for many reasons. They also favor big names. The “leaderboard” trends toward returning winners (like Tebow in 2009 or Ingram in 2010), even though only Ohio State’s Archie Griffin has won the Heisman twice, in 1974 and 1975. Who might make a rise from relative obscurity this year to win the trophy?

It should be clear by now that guessing is a fool’s errand. But the winner has typically been someone with a combination of a firm hold on the starting job, a place on a team that will contend and a role in an offense conducive to big numbers. Outside the top five preseason contenders, Washington’s Jacob Eason and Notre Dame’s Ian Book fit that profile. The winner could be someone better-known. It could also be someone you’ve never heard of.