One of the best known families in the Thoroughbred auction business is about to enjoy a huge day at the races. Mary Caldwell, the breeder of top Triple Crown candidate Brother Derek, is the widow of Tom Caldwell, who was Keeneland's director of auctions. She will be at Churchill Downs Saturday for the Kentucky Derby presented by Yum! Brands (gr. I). Joining her will be her two sons , auctioneers Cris and Scott Caldwell, and her two daughters, Georganna Happell and Karen Hammonds."It's the first time the brothers and sisters are going to get together at the racetrack ever, and we're really excited about that," Scott Caldwell said. "We've had some nice stakes winners that we raised, but this is our super horse, our once-in-a-lifetime horse."The Caldwell family sold Brother Derek, through Brookdale Sales, at the 2004 Keeneland September yearling auction. Cris Caldwell was in the auction stand at the time. The colt went for $150,000 to Utah-based pinhooker John Brocklebank. Last year, Brocklebank and his partner in B.C.3. Thoroughbreds, Shane Chipman, consigned Brother Derek, as agents for a partnership known as Timberline, to the Barretts March select sale of 2-year-olds in training. Cecil Peacock was the buyer, paying $275,000.Since then, Brother Derek has earned more than $1.1 million while winning the Santa Anita Derby (gr. I), Hollywood Futurity (gr. I), Norfolk Stakes (gr. II), and Catalina Stakes (gr. II)."It's been awesome," Scott Caldwell said. "It's making my mother's life right now. She lost my dad, and you can imagine what that was like for all of us. Then, to have this opportunity come along, it's just started her life all over again. She's excited again about the ranch and all the things that have to do with it. She's always stayed pretty active, but this has engaged her in the business again."The family patriarch, Tom Caldwell, died in 2001 of pancreatic cancer. Blessed with a distinghished presence and an authoritative voice, he followed in his grandfather and father's footsteps as auctioneer. In his position at Keeneland, he sold some of the best-bred and most expensive horses in the world. He also raised Thoroughbreds and cattle at his Gavel Ranch in Oregon."My mom sang opera when she was in high school and college," Scott Caldwell said. "Then, she met my father, and she had the choice of becoming an opera singer or a wife. Dad didn't give her a lot of options, so she became a wife."Tom Caldwell bred Brother Derek's first three dams. The colt's dam, Miss Soft Sell, was unraced. But his second dam, Solamente Un Vez, captured the 1985 Bay Meadows Lassie Stakes and two other added-money events. His third dam, Gavel Gertie, won seven races and was stakes-placed. Gavel Gertie's offspring included one of the Caldwells' most talented horses, Cuchillo, who captured the Allegheny Stakes in 1979 and the Sentinel Stakes the following year."Cuchillo was pretty well thought of, and he was in the Blue Grass Stakes (gr. I)," Cris Caldwell said. "But he grabbed a quarter and bled all the way (finishing eighth in the 11-horse field)."Brother Derek was foaled in California, but he spent many of his early days at Gavel Ranch, which Cris Caldwell runs for his mother."He was always a handful, but he still was tractable and really smart," Cris Caldwell said. "He never hurt himself, but he always wanted to use himself. He enjoyed his God-given speed."He was so fast, and he ran all the time, and he was very energetic. He also had a sense that he sure thought he was pretty good. We put him in with a moderate colt to provide him with a sacrificial lamb that he could abuse besides himself. That colt has been intimidated from that day forward. We sold him at a small Thoroughbred sale, and he has not started to our knowledge."Meanwhile, Brother Derek developed into one of the top runners in the country, and his dam, Miss Soft Sell, became a hot commodity. But neither Mary Caldwell nor her sons want to sell Miss Soft Sell even though they have received inquiries from prospective buyers."We've had a few offers for the mare, but in light of the fact that she belongs to an auctioneer's wife, they've been few and far between," Cris Caldwell said. "I think they know that my mom knows what she's doing. We tell them that we're not interested, and it pretty much stops right there. I think I would go (be sold) ahead of the mare."Said Scott Caldwell of Miss Soft Sell: "It's not a matter of price. She's just not for sale. I don't think my mom has any plans, now or in the future, of selling her. I think this will be our foundation mare, and we'll just go from there."Miss Soft Sell recently produced an In Excess filly at Mr. and Mrs. Martin Wygod's River Edge Farm in California. She and her foal are scheduled to be sent to Kentucky, where she will be bred to a yet to be determined stallion. Under consideration, said Cris Caldwell, are "half a dozen top stallions." Mary Caldwell will visit Kentucky farms with her family Friday to look at stallions, so she can offer her opinion about the final decision."We have no issues at all with Benchmark and River's Edge," Scott Caldwell said. "He's a great horse, and the mare has been bred twice to him and both of those foals are stakes winners. It's pretty hard to go against that. But you also realize with a $7,500 or a $10,000 stud fee, there is a maximum you can attain at auction and we found that out with this colt (Brother Derek) bringing $150,000 as a yearling. That was what he was worth. And now, we think, if we go with one of these horses (in Kentucky) that we've been considering, maybe we'll get the million dollar colt. There's a strong upside anyway."But if Tom Caldwell were alive, things might be different. Miss Soft Sell probably would soon have a new owner."I think my dad would have said, 'Sell!" Scott Caldwell said. "When we had five stockyards and I used to trade a lot of cattle, a couple of times I came home a little depressed. I wasn't making the kind of money I thought I should for all the work involved, and the famous quote my dad always gave me was, 'Son, you'll never go broke making a profit.' Obviously, there's lot of profit potential involved with this mare, but she's making my mom happy and that's most important to all of us right."After all, it's hard not to be sentimental, when a horse you bred is going to run in the Kentucky Derby."This is like the next Disney production coming on," Scott Caldwell said. (Brother Derek's trainer) Dan Hendricks has been a friend of the family forever and ever. With what he's been through and with a little farm in Oregon putting a horse of this caliber on the racetrack, it's pretty exciting."