One thing the Kentucky Derby (gr. I) has taught us over the years is that the winner can come from anywhere. And the same goes for the winner's sire.Included among the successful sprinter/milers now at stud who have sired winners of the 1 1/4-mile Derby are Our Emblem (sire of War Emblem), Distorted Humor (Funny Cide), and Elusive Quality (Smarty Jones). Holy Bull, whose best distance was between a mile and 1 1/8 miles (he did win the Travers Stakes at 1 1/4 miles), sired last year's winner, Giacomo. Maybe it is coming to the point that milers not only make the best sires, but also the best Derby sires.So how do some of this year's sires of major Derby contenders stack up? First off, there's a potent sprinter/miler in the group in the form of Langfuhr, whose son, Lawyer Ron, figures to be among the Derby favorites. Langfuhr (Danzig--Sweet Briar Too, by Briartic) won the Carter (gr. I), Vosburgh (gr. I), and Forego (gr. II) at seven furlongs, and the mile Metropolitan Handicap (gr. I). Langfuhr has bragging rights north of the border in a major "Derby," as his son, Wando, captured Canada's Derby equivalent, the Queen's Plate Stakes, in 2003.There's also something special about sires with previous Derby success. Maria's Mon, represented by major contender Cause to Believe, sired 2001 winner Monarchos. Another plus is that Maria's Mon (Wavering Monarch--Carlotta Maria, by Caro) is enjoying one of his best years at stud.Benchmark, whose son Brother Derek ranks atop Steve Haskin's Derby Dozen, will make for interesting reading if Bro' D gets the job done. Benchmark (Alydar--Winters' Love, by Danzig) didn't get to the races until September of his 3-year-old season, and didn't win his first stakes until age six. A Derby win will do plenty to boost Alydar's male line.A.P. Indy, Dynaformer, and Seeking the Gold, three of the best sires in recent years, are searching for their first Derby winners. A.P. Indy (Seattle Slew--Weekend Surprise, by Secretariat) came close in 2000 when his son, Aptitude, finished second to Fusaichi Pegasus. A.P. Indy's leading contender this year is A. P. Warrior.Aptitude, who is out of the Northern Dancer mare Dokki, himself has a Derby contender. Steppenwolfer, a member of his sire's first crop, figures to like the 10 furlongs.A.P. Indy has another son represented by a prime Derby contender. Old Trieste, who set the pace in the 1998 Churchill classic, will have front-running Toyota Blue Grass Stakes (gr. I) winner Sinister Minister represent him in this year's Run for the Roses. Like A.P. Indy, Dynaformer (Roberto--Andover Way, by His Majesty) imparts plenty of stamina to a pedigree. He's got a great shot this year with unbeaten Florida Derby (gr. I) winner Barbaro leading the way.Seeking the Gold (Mr. Prospector--Con Game, by Buckpasser) has a couple of live contenders in Bob and John and Jazil, who ran one-two in the Wood Memorial Stakes (gr. I). Six sons of Mr. Prospector either have won the Derby or have a Derby winner trace to them in male line. This just might be Seeking the Gold's year.Saint Ballado, last year's leading sire, died several years ago, and breeders still are looking for his successor. Sweetsouthernsaint just might be the one, especially if his son, Illinois Derby (gr. II) winner Sweetnorthernsaint, gets draped with the roses.