ARCADIA, Calif. – It may be more a question of which one than whether or not. Aidan O’Brien has won five renewals of the $1 million Breeders’ Cup Juvenile Turf, two more than any other trainer. By Friday evening that number might have risen, but will a sixth victory come from River Tiber or Unquestionable? “They’re two high-class colts who always stood out,” said jockey Ryan Moore, who himself probably helps answer the question. Moore has been aboard O’Brien’s five Juvenile Turf winners. He has ridden River Tiber in all five of his starts, Unquestionable in his last four. Moore on Friday gets a leg up on River Tiber, who has drawn well in post position 2. Frankie Dettori picks up the mount on Unquestionable. Jockey assignments aren’t everything. This feels like an unsubtle clue. O’Brien has a third, seemingly lesser, entrant, Mountain Bear, the first North American mount for jockey Dylan McMonagle. :: Breeders' Cup Shop: DRF Past Performances available now A field of 14 (no also-eligibles) was entered, a vast number of 2-year-olds going round sharp bends after a short run into the first turn. Luck can be as important as talent. Among the entrants in the last Breeders’ Cup race Friday (post time 4:40 p.m. Pacific) are three Breeders’ Cup Challenge race winners: Agate Road won the Pilgrim in New York; Can Group the Bourbon in Kentucky; and Carson’s Run, stuck out in post 14, the Summer at Woodbine. None are likely to handle the top O’Brien runners in a race captured 10 out of 16 times by an overseas juvenile. River Tiber is the 3-1 favorite over 4-1 Unquestionable on both the track’s morning line and Daily Racing Form’s, which seems about right. River Tiber won his first three starts, all as the favorite, handling heavy ground against overmatched maidens in his debut and skipping over firm going while beating 19 rivals in the Group 2 Coventry at Royal Ascot. River Tiber came back two months later, on Aug. 20, and finished third in the Group 1 Prix Morny at Deauville, then was third Sept. 30 at Newmarket in the Group 1 Middle Park, good performances though not River Tiber’s best. “Going into Deauville he had a little bit of a setback, unfortunately, and in his last run, Aidan just wasn’t quite happy with him going into the race,” Moore said. “I think he had a couple things against him, and he’s still been third in two Group 1s. Aidan feels he’s in better shape now than he was in both those races, and I’m expecting him to put up his best performance.” River Tiber, by Wootton Bassett, never has raced around a bend and has yet to go beyond six furlongs. Moore rode Meditate to victory in the Juvenile Fillies Turf last year off a similar profile and expressed zero concern about Friday’s longer distance. “I have no doubt he can get the mile,” Moore said. :: Get Breeders' Cup Clocker Reports from Mike Welsch and the DRF Clocker Team when you purchase a BC VIP Package! Unquestionable, another Wootton Bassett colt, might not have been quite as confident and fully formed over the summer as River Tiber but has done little wrong. Making his stakes debut July 5 in the Group 2 Railway, he took a late lead on top sprinter Bucanero Fuerte in the last half-furlong, only to give it up in the final strides and take a narrow loss. Favored next out in the Group 1 Phoenix, Unquestionable finished a well-beaten fourth with an excuse. “He had a problem in the gates, banged his head, and that’s why he ran bad,” Moore said. Unquestionable followed with a peak performance, a second to the high-class Rosallion racing around a bend in the seven-furlong, Group 1 Jean-Luc Lagardere on Oct. 1 at Longchamp. Moore cedes the mount to Dettori but said he got off the colt following the Lagardere thinking the Juvenile Turf would be a perfect spot for Unquestionable. Both horses have some pace, a plus in a race with but one confirmed front-runner, My Boy Prince, who may better suit this spot than might appear on first glance. :: BREEDERS’ CUP 2023: See DRF’s special section with top contenders, odds, comments, news, and more for each division My Boy Prince blazed to two wins in June and August sprinting over Woodbine’s Tapeta surface. Trainer Mark Casse stretched him to one mile and tried turf in the Summer Stakes, where My Boy Prince set the pace and was run down by Carson’s Run, finishing second by 1 1/4 lengths. Two things worked against him that day. My Boy Prince lost a shoe shortly before the start and it took about 20 minutes for the problem to be corrected. Casse also said an extremely wet summer created a turf-course bias, water settling on the inside portion of the track, conferring an advantage to outside closers like Carson’s Run. My Boy Prince came back after the Summer and easily won the restricted Cup and Saucer, a turf route Casse called “a workout.” Santa Anita’s homestretch, Casse pointed out, is far shorter than Woodbine’s, a plus. :: Bet with the Best! Get FREE All-Access PPs and Weekly Cashback when you wager on DRF Bets. Casse also sends out Can Group, who upset the Bourbon at Keeneland over 1 1/16 miles but is a worse fit for the shorter Juvenile Turf, where he’ll be trying to rally into what should be, at most, a moderate pace. The same concern applies to Agate Road, who has come from last and second-last to win his last two starts. “I think that’s just who he is. He’s going to have to get lucky,” trainer Todd Pletcher said. “He’s got a big turn of foot if we can get him into the clear.” Endlessly leads the California contingent. He is a three-time winner from three starts, all by more than two lengths, the last two in Grade 3 competition. That’s solid form, albeit on a circuit that never has produced a Juvenile Turf winner, and trainer Michael McCarthy believes Endlessly has further improvement coming. Endlessly is a son of Oscar Performance, who won the 2016 Juvenile Turf at Santa Anita for Endlessy’s owner and breeder, Amerman Racing. Stay Hot is a locally based maiden winner of promise, while longshot Tok Tok ran into a freeway traffic jam during the stretch run of the Bourbon, where he was fifth. He adds blinkers, a strong move for trainer Graham Motion. Carson’s Run took a significant step forward winning the Summer on Sept. 16, his most recent start. He’ll need something even stronger to overcome his poor draw. Air Recruit, Liam’s Journey, and Fulmineo complete the field. The two O’Briens can complete the exacta. :: Want to learn more about handicapping and wagering? Check out DRF's Handicapping 101 and Wagering 101 pages.