Ahead of the 2026 flat racing season, renowned trainer Aidan O'Brien showcases his promising lineup at the Ballydoyle stables. Special focus is placed on three-year-old colts like Albert Einstein, tipped for the Guineas, and Derby hopefuls like Benvenuto Cellini. O'Brien's strategy revolves around nurturing speed and potential across events, from Guineas to sprinters and seasoned stayers. Insights reveal the meticulous planning behind each horse's training regime and expected performance, painting an exciting picture of the racing season ahead.
The most dominant trainer in flat racing is, undoubtedly, Aidan O'Brien. The master of Ballydoyle has saddled over 400 global Group One winners during his illustrious career and, in 2025, came within one of matching his own record of 28 Group One winners in a single season, which he set in 2017.
Ahead of the new flat racing season, Aidan O'Brien spoke to AtTheRaces to guide readers through his team for 2026.
*All quotes taken from AtTheRaces*
Aidan O'Brien Stable Tour 2026
Three-Year-Old Colts - Guineas Horses
Albert Einstein
The number one horse for the 2000 Guineas is Albert Einstein. He’s done very well physically. He’s big, powerful and very rapid. He’s unbelievably quick. We won’t know whether he’s going to stay a mile until he runs over it. The stride people, the heart people and the pedigree people all say he’ll get a mile, but he’s a very quick thinker, he’s quick to leave the stalls, he’s quick into his stride, so we aren’t going to know until he’s asked to do it in a race. He’s going to need to slow himself down and relax.
Our intention is to train him for the Guineas without ever having come off the bridle. Our focus is getting him to relax. I’m not sure we’ve had a horse that is as quick mentally as him. When we started working the two-year-olds last spring, we thought they were all no good, as he was so far in front of them all. We thought he was the only real one we had. We know now that a bunch of the others went on to win Group 1s, so that tells you something.
He won his two starts very easily and the runner-up in the second one went on to win a Group 1 later in the season. He picked up a little fracture that day and that was why he didn’t run again, but that has healed perfectly and it wouldn’t be on our minds going forward. He’s very exciting. He’s the horse everyone is dreaming about.
Causeway
He could be one for the Madrid Handicap at Naas. We’ll see what the handicapper does first. He’ll go up in trip after that and sure he could be a Paddington. He’s a big horse and should progress well. I think he could be a very good horse, I’m just not sure how far he’ll stay as he shows plenty of pace.
Constitution River
He could be a very good horse. He had a mishap after winning the Futurity Stakes and that’s why he didn’t run after that. He looks to be one to start off in a Derby trial and he could be one for the Prix du Jockey Club, but I wouldn’t completely rule out the Irish 2,000 Guineas either.
Gstaad
He’s being trained for a Guineas. The way the lads are talking, I’d say one other will go to Newmarket with Albert Einstein and it will either be him or Puerto Rico. Whichever one doesn’t go to Newmarket will go to Longchamp for the French Guineas. Longer term, I could see him getting a mile-and-a-quarter, and it wouldn’t be a shock if he ended up in something like a Cox Plate.
Puerto Rico
Sure, I did a very bad job with him last year, didn’t I? I was running him over six furlongs early in the season. We ran him in the Richmond Stakes at Goodwood, and the poor fella hardly touched the ground - he was flat out the whole way! In fairness to him, he missed two months early in the year and was probably playing catch up all the time. It was only when he stepped up to seven furlongs later in the season that he caught up and really started to thrive. He improved again when he stepped up to a mile.
He’s scopey, he’s strong and his mind has really gone the right way. He’s being trained for the Guineas, but it won’t be decided which one until closer to the time. He could either go to Newmarket with Albert Einstein or potentially go for the French Guineas instead.
Trojan Warrior
He won his only start at the Curragh. He could be one for the Irish 2,000 Guineas and could run in the Tetrarch Stakes before that.
Christophe Soumillon riding Precise (R, purple) win The bet365 Fillies' Mile at Newmarket. (Getty)
Three-Year-Old Colts - Derby Horses
Action
I thought he ran very well in the Futurity Trophy. He could be one for the Epsom Derby and we’ll start him off in a trial for it.
Benvenuto Cellini
He looks like one for Epsom. He has done very well over the winter. He’s a great mover and I think Epsom will suit him.
Christmas Day
He’ll be one to get started in Derby trial. He should stay well.
Dorset
He’ll probably start off in a Derby trial and could be one for the Prix du Jockey Club potentially.
Hawk Mountain
He is one that will be trained for the Derby or the Prix du Jockey Club. I’d say he’ll be very comfortable at a mile-and-a-quarter, but we’ll see how his trials go.
Isaac Newton
He’s a dark horse. He’s much better than we’ve seen on the track so far. He’s one that is likely to start off in a Derby trial. He could improve a good bit from what we’ve seen so far.
Montreal
He won very easily at Leopardstown and is an exciting horse. He could be one for the Derby, but we haven’t picked out a starting point for him yet. He’s not short of pace, but we think he could stay a mile-and-a-half. He could be a dark one for the Derby.
Pierre Bonnard
We’re very happy with how he has wintered. He’s very straightforward, very relaxed, very chilled. Christophe was always super impressed with him. He’s being trained for the Derby and will most likely run in the Ballysax Stakes and the Cashel Palace Hotel Derby Trial at Leopardstown before then.
Straight Up
He could be one for the Prix du Jockey Club. He was disappointing in the Autumn Stakes, but I’d forgiven him that as he ended up too far back and couldn’t win from there. He’s a lot better than that run and could be a fair horse.
Three-Year-Old Fillies
Beautify
She looks the right type for the French Guineas. A turning mile will suit her well.
Diamond Necklace
She’s very much like her sire St Mark’s Basilica. She’s made great progress from two to three. She’s very strong, very natural and takes no training. We were a bit surprised just how much she showed last season, and we were happy to finish up with her for the season, as it was all going to be about her three-year-old campaign with her. Christophe was always very besotted by her.
Listening to the lads, it’s sounding like she could be more like to go for the French Guineas and Precise could go to Newmarket. That seems to be the thinking at the minute. After that, she could be one for the Prix de Diane back in France.
Drop Dead Gorgeous
She hasn’t run yet, but we think she’s very smart. There’s a maiden at Naas next week, and so she might start there.
Precise
I was very impressed with her in the Fillies’ Mile. I wasn’t expecting Christophe to drop her out as much as he did, but she was coasting home in the final furlong. We brought her to the Breeders’ Cup, but she started to cough and her bloods weren’t right, so she couldn’t run. Though, travelling over and getting that experience probably crowned her in mental terms.
She’s not overly big, but she’s still up 30kg on her racing weight from last year, which is unusual for a filly that isn’t overly big. At the moment, the plan for her is the 1000 Guineas at Newmarket. We think there’s a good chance that she might stay a mile-and-a-half, so the Oaks could be on her agenda if all went well at Newmarket. She has loads of personality, she relaxes, and we’re excited about her.
Simply Astounding
She’s a very good filly, but she picked up an injury in her second start last season and didn’t run again for the rest of the year. We had her back and everything was flying, but she went a little wrong on us last week, so we had to stop again. I’d imagine she’ll miss the Guineas now, but we’ll hope to have her back in time for Royal Ascot.
True Love
We’ll train her for the Guineas. She’s very fast, but we’ll give her the chance to show us she can stay a mile if she can.
Wayne Lordan on Lambourn leads the Betfred Derby during Derby Day. (Getty)
Three-Year-Old Sprinters
Brussels
He’s a sprinter and will be on a programme to get him to the Commonwealth Cup.
Charles Darwin
He could be a very good sprinter. He’ll run in the trials for the Commonwealth Cup and all being well will get to the race itself at Royal Ascot in good shape. He’s a real block of a horse, very powerful.
Mission Central
He will be a work partner for Brussels and Charles Darwin. He’ll run in those sprints too and should pay his way.
Older Horses - Milers and Middle Distance
Expanded
Things didn’t fall right for him last year, but he’s back in and moving well. We’ll look to get a run into him and then go for the Lockinge Stakes at Newbury.
Jan Brueghel
He will be trained for the Coolmore Coronation Cup at Epsom, and we’ll look to get a run into him before it.
Lambourn
We are training him for the Coolmore Coronation Cup at Epsom. He’ll have a run before then, potentially in the Mooresbridge Stakes at the Curragh.
Minnie Hauk
She had a great winter and looks in super order. She’s twice as wide as she was last year. Her first target will be the Tattersalls Gold Cup at the Curragh, and she might run in the Mooresbridge Stakes at the Curragh as her prep for that. She could go onto the Prince of Wales’s Stakes at Royal Ascot in the summer.
The Lion In Winter
He has done well over the winter, and we are training him with a view to the Lockinge Stakes.
Twain
We didn’t get him to the track last year, which was a real disappointment, probably the biggest disappointment of the season really. It was a series of niggly things rather than a big setback, so it was frustrating. He’s being trained for the Lockinge at Newbury and will have a run before then all being well. We see him as a miler.
Older Horses - Stayers
Illinois
He’s one for the staying division again. He did well last year and can hopefully win a big one this year.
Scandinavia
He’ll be going down the staying route. He’s a big, long-striding horse and we’re looking forward to him this year. We have him entered in Dubai, but I’d imagine he won’t go. He’ll more than likely go for the Vintage Crop and the Saval Beg.
