Nitrogen a Winner in Whitney Defeat

If you were standing by Mark Casse's barn at Saratoga Race Course the morning of Aug. 9, you likely would have thought he had a big winner the day before. Every passerby—whether by car, golf cart, or feet—would pause to wish the dual Hall of Famer congratulations on the filly's big run. However those congratulations were not for a winner, but the runner-up in the $1 million Whitney Stakes (G1): Nitrogen. The scenario was unlike any other one Casse had experienced before. "No, not when I've lost. You get it when you win," Casse said when asked if he'd every received this much congratulations for losing a race. "I've heard that about 100 times. Everybody was coming to me in the grandstand." Although Nitrogen's defeat was a loss in name only. In reality, the filly had run one of the best races of the season and defeated all but one of the nation's best older males, justifying her connections' faith in her abilities. "I couldn't be more proud of her," Casse said. "What a field that was yesterday. Yeah, she got beat, but it took the Horse of the Year to beat her. "I seldom get emotional about a horse race, but I actually got a little teary after the race because I was just so proud of her." Part of that emotion likely came from the added pressure and anxiety. The D. J. Stables homebred had clearly marked herself as one of the leading, if not the leading, older mares in the distaff division. She would have been an odds-on choice to win last month's Shuvee Stakes (G2) and the Aug. 29 Personal Ensign Stakes (G1) against her own sex. Instead, they wanted to test just how good their filly was. Whether or not that was the right choice was being debated by anyone with an opinion in the lead-up. If it didn't go well, would it negatively impact the rest of her career? "To me, my job is to protect them," Casse said. "I wasn't worried, but I was worried that I had thrown her out to the wolves. If I was wrong (about running in the Whitney), I would've beat myself up." In the field was Sovereignty, the 2025 Horse of the Year, Kentucky Derby (G1), and Belmont Stakes (G1) winner; Magnitude, the Dubai World Cup (G1) and Stephen Foster Stakes (G1) winner; White Abarrio, a four-time grade 1 winner who took the 2023 Whitney and Breeders' Cup Classic (G1); and grade 1 winners Baeza and Antiquarian. The waters could not be any deeper, but nothing about the filly's career has been normal. In 2024, she was named Canada's champion 2-year-old filly despite ending the year as a maiden. In 2025, she dominated her filly turf peers in the first half of the year before swapping to dirt and taking down the Alabama Stakes (G1), earning her an Eclipse Award for America's champion 3-year-old filly. So what was one more challenge? Nitrogen handled it like the pro she consistently has proven to be. After stumbling at the start, grabbing her right-front foot and causing an abrasion, Nitrogen still managed to get a better break than Magnitude on her inside and force him to race behind her on the rail as they entered the backstretch. With Hall of Famer John Velazquez aboard, she then took heat from Antiquarian around the far turn and entering the stretch. Sovereignty revved up to his full potential and surged on by, but Nitrogen kept battling away behind him and refused to let Antiquarian or any of the others by her. "She is just a fighter. She just amazes me—the consistency," Casse said. "We had a huge crowd yesterday, she doesn't care about anything. It's like, 'bring them on.'" That huge crowd showed their appreciation as they cheered the filly's brave effort upon her return to the frontside. On Sunday morning, she was no worse for wear and all was good with her right front. With her strong effort against the boys adding to wins in the Ogden Phipps Stakes (G1) and Bayakoa Stakes (G3), a second in the Apple Blossom Handicap (G1), and a third in the Azeri Stakes (G2), Nitrogen has elevated herself into a clear leading position for another championship honor as the leading older dirt female. Depending on how the remainder of the year shakes out, she also has placed her name in the Horse of the Year conversation. As for her year, it will be back to the girls for Nitrogen as Casse plans a start in the Spinster Stakes (G1) Oct. 4 at Keeneland, getting her a run over the track that will host the Oct. 31 $2 million Breeders' Cup Distaff (G1).