When Heisman Trophy voters fill out their ballots six weeks from now, Ty Detmer may find his candidacy was derailed by a flock of attacking Ducks.

In Brigham Young's 32-16 loss to Oregon, the Ducks showed Detmer to be as human as the rest of the leading candidates and reopened a race many had conceded to the latest model out of the Cougar quarterback factory.In the overhyped world of the most prestigious award in college athletics, one game can make or break a candidacy. When voters can't see each game of every top contender and statistical comparisons are difficult because of differences in offensive styles or positions, many rely on the performances that stick in their minds.

Doug Flutie set the NCAA career total-offense record at Boston College in 1984, but he won the Heisman with his improbable last-second touchdown heave to Gerald Phelan that pulled out victory against Miami.

Notre Dame's Tim Brown caught 39 passes for 846 yards and ranked sixth in the nation in all-purpose yardage in 1987, but it was his two punt returns for touchdowns in a nationally televised September game against Michigan State that cemented his Heisman bid.

Likewise, many candidates run off the road to the Heisman when they come up with a bad performance in front of the television cameras.

Dee Dowis, Air Force's option quarterback with a six-touchdown game under his belt, was the No. 1 candidate in the minds of many through the first six weeks of last year. But in his one game in the spotlight, against Notre Dame, he could not handle the bigger, faster Fighting Irish and finished with less than 100 yards rushing. Goodbye, Heisman.

John Elway always found himself on the short end of the Heisman voting because he was unable to win the big game at Stanford. (Sound familiar, Denver Bronco fans?)

His 1982 Heisman candidacy unraveled in September when he was outgunned down the stretch against Arizona State by an little-known quarterback named Todd Hons. That also was the year Stanford lost to California on the five-lateral kickoff return with no time left.

Detmer became the 1990 front-runner when he led BYU to its 28-21 victory over preseason No. 1 Miami in the second week of the season, and bolstered his credentials by engineering comeback victories over Washington State and San Diego State.

But all that work may have been rendered moot by a swarming Oregon defense that sacked Detmer five times - once for a safety - and grabbed five interceptions, including three in the end zone.

Detmer still produced another stellar set of statistics against the Ducks, completing 33 of 57 passes for 442 yards and two touchdowns. But the lingering impression coming out of that game is that Detmer couldn't produce the heroics of the previous two weeks.

In Detmer's case, that could be vital. Because the Cougars play in the Western Athletic Conference, hardly anybody takes the quality of BYU's schedule seriously despite efforts by the school to include more top-flight opponents. The level of competition certainly diluted the Heisman statistics of Detmer's predecessors.

When Jim McMahon was setting all those NCAA passing records in 1981, he was doing it against the likes of Utah State and Long Beach State. The Cougars even lost to Nevada-Las Vegas that season. McMahon wound up far behind Southern Cal's Marcus Allen and Georgia's Herschel Walker in the Heisman race.

Two years later it was Steve Young's turn to put his name in the NCAA record book. But the list of opponents was much the same, and BYU's lone loss came to a Baylor team that finished 7-4-1. Young finished second in the Heisman voting behind Nebraska's Mike Rozier.

Now the question is which Detmer impression will be on the minds of Heisman voters when they fill out their ballots - BYU's first victory over a No. 1 team, the consecutive comeback wins or the mistake-filled loss to Oregon that yielded 442 yards passing and just 16 points.

One thing is certain - Detmer's stumble evens the race. He still may be slightly ahead of the pack, with an average of 431 passing yards and three touchdowns a game, but the margin no longer is so great that another contender can't overtake him.

Michigan's Jon Vaughn is averaging nearly 200 yards rushing a game and is the only Wolverine running back in history to record back-to-back 200-yard games. Shawn Moore is passing for 224 yards and almost three touchdowns a game while directing a Virginia offense that is averaging 51 points a contest.

David Klingler could give Houston back-to-back Heismans with his 440-yard passing average, helping those Cougars average 37 points a game. And it only would take a couple of kick-return touchdowns by Raghib Ismail to thrust Notre Dame's rocket back into the race.

At any rate, don't start fitting Ty Detmer for the Heisman crown yet. He still has a way to go to earn it.