Big Brown made waltzing through the first two jewels of the Triple Crown look easy. Speed, versatility, durability, temperament -- he appears to have it all.

But as every horseman will tell you, the mark of a champion is courage and heart. And those characteristics always show up in the heat of battle, eyeball to eyeball.

So far in five races, the Kentucky Derby and Preakness Stakes winner has yet to spar.

Until Big Brown gets some decent competition, he'll just be a good horse that was lucky enough to be in a crop of mediocre 3-year-olds. In the first two legs of the Triple Crown, Big Brown has seen more chopped liver than guests at a bar mitzvah reception.

The 1 1/2-mile Belmont Stakes on June 7 could offer a defining moment.

Macho Again and Ichabod Crane, followers in his Preakness wake, will be back. So will Denis of Cork, Tale of Ekati and Anak Nakal, who finished up the track at Churchill Downs.

Big Brown's competition probably won't come from them. Nor will it come from a few other stragglers who might appear.

Quite likely, it'll be from lightly raced colt Casino Drive, whose pedigree reeks of stamina and who has been pointed to the Belmont Stakes for months.

A half-brother to the last two Belmont winners, Jazil and the filly Rags to Riches, Casino Drive is out of the dam Better than Honour. Casino Drive's last effort was quite impressive -- he won the Peter Pan Stakes by 5 3/4 lengths at Belmont Park on May 10. The Japan-based colt coasted home in the 1 1/8-mile race in a swift 1 minute, 47 4/5 seconds without any urging.

Coincidentally, Big Brown's rider, Kent Desormeaux, rode Casino Drive in the Peter Pan. He says Casino Drive is the only horse that can match Big Brown's stride. He's gone so far as calling their meeting in the Belmont a "cold exacta." But in which order?

Of course, let's not forget the Churchill Downs also-rans taking advantage of the five weeks between the Derby and Belmont. Such horses have been dangerous in the past.

Birdstone, the eighth-place finisher at the 2004 Derby, wore down Smarty Jones at the Belmont to stop his Triple Crown bid. Smarty Jones' rider, Stewart Elliot, was justifiably criticized for moving his colt too soon and not leaving something in the tank for the stretch run.

A year earlier, Derby favorite Empire Maker finished second to Funny Cide in Louisville despite a bruised foot. Empire Maker returned in the third leg to thwart the New York-bred gelding's bid to become the 12th Triple Crown champion.

The unpredictable often happens at the Belmont, too.

In 2002, War Emblem stumbled at the start. Jockey Victor Espinoza expended much of the colt's energy getting him back in the race, allowing Sarava -- the highest-priced long shot in Belmont Stakes history -- to win the race.

Charismatic's ill-fated stretch run in the 1999 Belmont, where he was pulled up after the finish with an injury, allowed Lemon Drop Kid -- ninth in the Derby -- to take over at the eighth pole and hold on to win by a head.

Speaking of questionable rides, what about Desormeaux's run on Real Quiet in the 1998 Belmont? The Triple Crown was lost when he misjudged -- by his own admission -- what Victory Gallop had left in the last few jumps to the wire.

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The Belmont Stakes -- the oldest and longest leg of the Triple Crown -- clearly is the toughest. Many call it a rider's race, in which the jockey must be a supreme judge of speed, pace and stamina.

Everything has to go right for both pilot and horse. Every jockey will be trying to take Big Brown and Desormeaux out of the Belmont, even if it requires sacrificing their own mounts.

Desormeaux has missed winning the Belmont twice -- finishing second with Medaglia d'Oro in '02 and Real Quiet in '98 -- and hasn't ridden in the Belmont in six years.

One has the feeling he'll spend the next two weeks getting to know every inch of those sweeping turns and the length of that intimidating stretch at America's biggest racetrack.