EAST BOSTON, Mass. – David Amiss, Vernon Bush, and Taylor Hole, who have a combined 92 years of experience in the saddle, came back to Suffolk Downs this season believing they could still be competitive. Midway through the meet, expectations have been exceeded. Amiss, 49, finds himself in the pleasant position of being atop the leaderboard with 34 wins through July 9, and the 43-year-old Hole sits in second with 24. Bush, who turns 53 next month, has 18 victories and is tied for fourth with the decades-younger Gary Wales. “I am surprised at how well things are going,” said Amiss, who has witnessed Tammi Piermarini take home leading rider honors for the last four consecutive years and five times overall. “Coming into the season, I certainly didn’t expect it.” “This is one of the best years I’ve ever had,” said Hole, who started his career in 1991 and has made 1,961 trips to the winner’s circle. “I’m getting a lot of opportunities now, which is what it’s all about, and am making the most of them.”Bush, who was known as Billy Bush when he started riding at the old River Downs in 1978 and has 3,202 wins from 25,012 mounts, said he’s having more fun than ever and is the happiest he’s been in a long time. He has good reason. “I have finally and honestly come to grips with my addictions,” said Bush, who credits the unwavering support of his current wife, Colleen, and ex-wife Lynette. “I had a three-day blackout last November but I’ve been sober now for eight and a half months. Cocaine was my problem, but I’ve been off that since ’95. I thought I could drink and handle it, but that didn’t happen.” Despite being ruled off several times in different jurisdictions, Bush’s talent never left him. “As a rider, my mental attitude and aptitude is stronger now,” said Bush, who admitted that he rode while impaired on cocaine in the past. “I don’t know that I can go toe-to-toe with the younger guys physically, but I can use my knowledge. It hasn’t been hard to rebuild my trust with the trainers. They tell me they see something good in me and they respect me now.” Hole, who stands 5-foot-9 and tacks 119 pounds, attributes his successful season in part to being in better physical shape than he has in ages. “I changed my diet to eliminate all processed food and add more fruit and vegetables, so I can eat a lot more and no longer have to starve myself,” he said. “I was doing it all wrong.” Amiss, who started riding in 1991 but was sidelined from 2001-2005 with shoulder injuries needing surgical repairs, has 1,105 career wins from 9,450 mounts. The most recent are among the most satisfying. “I make sure every day counts,” Amiss said. “With racing only three days per week, you have to take advantage of every opportunity.” Each of the three multiple stakes winning jockeys said he is pleased to see the others also enjoying this level of success at the advanced stage of their careers. “Vernon is 10 years older than me and Davis is a couple of years older, but I look up to them,” Hole said. “They give me ambition and inspiration.”  Trainer Allison Hassig takes a double shot at the $25,000 Isadorable Stakes for Massachusetts-breds Saturday when she sends out Doublicious and Delycius Lady in the six-furlong test for fillies and mares. Doublicious, who won the Louise Kimball Stakes here at the same distance in her only 2013 start, will be partnered with regular rider Amiss. Delycius Lady, previously trained by co-breeder George Brown, makes her second start of the season after graduating in a $5,000 maiden-claiming affair at 5 1/2 furlongs June 16.