$5,000 Claim Unsolved Mystery Keeps Rolling for Rivera

The biggest concern that Luis Rivera, Jr., had when he claimed Unsolved Mystery for $5,000 a year ago was whether he would be able to recoup his money. "For someone like me it was a big gamble," said the former jockey. Suffice it to say the reward has far exceeded the risk. When Unsolved Mystery won last Saturday's second race at Monmouth Park—a $12,500 starter optional claimer—it marked the 7-year-old mare's seventh consecutive win. All of those have come since the Rivera-owned La Familia Stable made that July 27, 2025 claim, with five of the wins at Monmouth Park. If not for being second by a nose in the race that Rivera took her, the winning streak would be nine. "She gets all of my attention," said the 59-year-old Rivera, a part-time owner and trainer who now makes his living by exercising horses in the mornings. "She was the only horse I had then so I was able to take care of her all of the time. If you have 20 horses you are hurrying to give them the attention they need and you often have to rely on others to help. "I do everything with her. My focus is all on her." A Kentucky-bred daughter of Goldencents, Unsolved Mystery had a pedestrian record before coming into the care of Rivera, who won 1,560 races as a jockey in a career that began in 1987. After starting her career in 2021 for trainer John Sadler at Del Mar, she did go on to win the Arizona Oaks at Turf Paradise in 2022. Overall, her 28 career starts have come 12 different tracks, with Rivera being her 10th different trainer. Eight of her 11 career wins have come since July 11, 2025. Rivera said he was just taking a shot when he claimed her, giving him something to occupy his time after he finished exercising horses for other in the mornings. "I liked that she was dropping in class (from $12,500) when I claimed her," said Rivera, who now has a two-horse stable after claiming Captain Oats for $7,500 last Friday at Monmouth Park. "But you have to be careful with those types of claims. You never know what's wrong with the horse. "You have to do your research and then look at the horse physically and then ask yourself if you can help that horse win." For Rivera, who hails from Rio Piedras, Puerto Rico, the investment at the time was significant, but he needed something to stay busy. Now he has a horse that refuses to lose. "It doesn't always happen like this," he said. "But I give her good care and I have picked the right spots for her and she has responded. She has been terrific. She has been unbelievable. "I can't believe it myself. She just keeps winning." Two of the wins during the current streak aren't technically credited to Rivera, since he transferred her to fellow trainer Eli Betancourt for a pair of races at Parx recently. "They have a rule at Parx that you can't be the trainer for a horse in a race there if you exercise for other trainers in the mornings," he said. "I didn't want to give that up because that's where I make my living. So I sent them to him for those two races." Rivera, who turned to training in 2018 "to keep busy" after he stopped riding full-time in 2017, is no stranger to unique accomplishments. On July 24, 2020 he pulled off the rare trifecta of being the owner, trainer and rider when Strawberry Road won a race at Monmouth Park. Even after doubling his stable, though, he continues to give Unsolved Mystery most of his attention. She is 4-for-4 this year after going 4-for-5 (with a second) last year and she has won six races at Monmouth Park over the past year. Rivera said Unsolved Mystery will get a break "for a few weeks" before he looks for another race at Monmouth Park in September. "She has earned some time off," he said.