Exogenous, a homebred from Vernon Heath's Centaur Farms in Kentucky, has a well-balanced pedigree of both speed and stamina. However, she's already proven that a route of ground is forte, having now won back-to-back 1 1/8-mile grade I races at Belmont Park for trainer Scotty Schulhofer. Prior to her coming out party in September, the gray 3-year-old filly placed in three consecutive grade I stakes at nine, 12, and 10 furlongs.From a perspective of the Oct. 27 World Thoroughbred Championships, Exogenous has Breeders' Cup written all over her.Let's start with her sire: the big bay Unbridled. Unbridled was raced by Mrs. Francis Genter and trained by Carl Nafzger and was named champion 3-year-old colt in 1990 after winning both the Kentucky Derby (gr. I) and Breeders' Cup Classic (gr. I) at Belmont Park. While being a son of the speed-influence Mr. Prospector, Unbridled was at his best at 3 and at his best at 1 1/4 miles. As a sire, Unbridled stood originally at Graham Beck's Gainesway Farm near Lexington before being sold to a syndicate headed by Seth Hancock and his Claiborne Farm before the 1997 breeding season. A foal of '98, Exogenous is from that first crop of foals.As a sire, Unbridled has had excellent results in Breeders' Cup races. While he has only had five starters, he is represented by two winners, and Banshee Breeze, who finished second twice in the Distaff (gr. I) in 1998 and '99. Both of Unbridled's winners bagged the Juvenile: Anees in 1999 and Unbridled's Song in 1995. Exogenous' dam, Tangled Up in Blue, was bred in Kentucky by the late Ben P. Walden Sr. Now an 11-year-old, Tangled Up in Blue has gone through the auction ring four times. Her first time was as a Keeneland November weanling in 1989, where she was sold for $40,000. She failed to meet her reverse at $85,000 at the next year's Keeneland September yearling sale, then was a $270,000 sale juvenile in 1991 at the Fasig-Tipton February sale of 2-year-olds in training. Finally, she was purchased by Centaur Farm forshe was sold for $51,000 at the Ocala Breeders' Sales Co.'s winter sale in 1996. Exogenous is the second foal out of Tangled Up in Blue since she was purchased by Centaur.Phone Trick, broodmare sire of Exogenous, has sired two Breeders' Cup winners: Phone Chatter, winner of the Juvenile Fillies (gr. I) in 1993, and Favorite Trick, Juvenile (gr. I) winner in 1997 and that year's Horse of the Year.Key to her pedigree is Exogenous' second dam, stakes-placed Count On Kathy. Bred in Maryland by H.J. Kossow, Count on Kathy won four of 19 starts and placed in six stakes and is the dam of two stakes winners: Count on Change and T. V. Countess. Count on Change earned $233,699 while racing in Canada and T. V. Countess earned $117,237 while winning the Politely Stakes. T. V. Countess went on to produce Countess Diana, champion 2-year-old filly of 1996 and winner of that year's Breeders' Cup Juvenile Fillies at Woodbine, and two other stakes winners.