Nitrogen has done enough to make herself the horse to beat in the $2 million Breeders' Cup Distaff, but the favorite's position is hardly secure. The reigning champion 3-year-old filly comes to Keeneland off a controlled 2 3/4-length victory in the Grade 2 Beldame at Belmont Park, while Fully Subscribed and Splendora arrive with form strong enough to turn the 1 1/8-mile championship into a genuine three-way examination.
The Beldame was Nitrogen's first start since her remarkable 12 3/4-length Ogden Phipps romp and her runner-up finish behind Sovereignty in the Whitney. She dictated the pace against four rivals and completed the nine furlongs in 1:48.36, according to NYRA's race report. Trainer Mark Casse chose the New York prep rather than the Jockey Club Gold Cup, giving Nitrogen a confidence-building trip and a Breeders' Cup entry-fee credit in the process. The official Breeders' Cup contender profile lists the Beldame as her final Distaff tuneup. citeweb:11citeweb:1
Her appeal is obvious: Nitrogen owns elite numbers when she is producing her best run, and she has the tactical speed to avoid depending on a collapse up front. She also showed in the Beldame that she can control a race without being fully extended. The concern for handicappers is whether her biggest figures travel as effectively to Keeneland; recent analysis has noted that her fastest performances have largely come at Saratoga. That makes the post position and early pace especially important, because Nitrogen is most dangerous when Jose Ortiz can place her in striking range without forcing the issue.
Fully Subscribed is the principal danger and arguably the most interesting value play. The Chad Brown trainee was beaten decisively by Nitrogen in the Ogden Phipps, but she has since won three straight graded stakes, including a more-than-nine-length Personal Ensign victory and the Grade 1 Spinster over the same Keeneland track and distance as the Distaff. Her stalking style gives her a cleaner route than a deep closer if the early fractions are moderate, while her recent progression suggests she is arriving at the right time. Recent handicapping analysis likewise identifies her as a candidate to narrow the margin from the Phipps. citeweb:6
Splendora offers a different challenge. Last year's Breeders' Cup Filly & Mare Sprint winner has won five of six in 2026 and has successfully stretched her speed around two turns, most recently taking the Grade 2 Locust Grove by 5 1/4 lengths. The question is not whether she can make the lead; it is whether she can carry that advantage through nine furlongs against deeper Grade 1 company than she has faced recently. Her speed makes the draw meaningful: an inside post could create pressure, while a far-outside slot could force her to spend energy before the first turn.
The early market reflects that hierarchy. Nitrogen has been listed around even money to 5-2 in futures markets, with Fully Subscribed next and Splendora among the next tier, while the official field and post positions remain pending. Casse has also worked Nitrogen at Keeneland, with Paulick Report noting a half-mile solo breeze on Oct. 14, her first work since the Beldame. citeweb:8citeweb:9citeweb:13
For now, Nitrogen deserves top billing, but the betting decision may come down to price rather than preference. A short quote would demand confidence that her Saratoga-level brilliance is available again; a more generous number would make her the logical key. Fully Subscribed is the mare most capable of turning that favorite into an underlay, while Splendora needs the right trip and must answer the distance question. Once the draw is complete, the pace scenario should decide whether this is Nitrogen's coronation or the race in which her challengers finally cash in on their momentum.