This angle has relevance in the 2024 Breeders’ Cup Classic as Aidan O’Brien is bringing in City of Troy for his first and final start on dirt before he heads off to the breeding shed. I have heard a number of pundits mention that this move is not something O’Brien typically does, but I would argue this move is fairly common with O’Brien but it is just that he has not done it in seven years. Between 2000 and 2017, he started ten turf horses in the Classic where it was their final race.

O’Brien almost pulled off the turf to dirt move in 2000 but finished a neck short with Giant’s Causeway against Tiznow. That was Giant Causeway’s first try on dirt and last race overall as it was for Declaration of War when he ran 3rd in the Classic in 2013. Henrythenavigator also finished second in Breeders’ Cup Classic in his last start, but that was run over the synthetic surface at SA, so I am going to exclude him from analysis. I did leave George Washington in the analysis because he was retired after finishing 6th in the 2006 Breeders’ Cup Classic but returned to racing the second half of 2007 due to fertility issues. Unfortunately, he broke down in the Classic that year and was humanely destroyed. I used the 2006 data for that entry.

Overall O’Brien is 17-0-2-1 in the Classic and I just mentioned his three horses that finished in the money. It seems like he runs horses in the Classic often enough that seem to be an afterthought at the end of their careers to increase the stud value if they can win or run competitively on dirt. I think one potential difference this year is that City of Troy has been pointed to this race for a long time, so it does not seem to be an afterthought at the end of season before retirement as some of his other starters appeared to be. Other horses that he ran in the Classic as their first start on dirt and last race of their career have been the great Galileo (6th), who was undefeated until he was beaten by Fantastic Light in the Irish Champion Stakes in his penultimate race, followed by his run in the Classic before retirement. Add George Washington (6th), Churchill (7th), Gleneagles (8th), Duke of Marmalade (9th), Black Minnaloushe (10th), Oratorio (11th), and George Washington (again - DNF this time) as O’Brien charges making their last start in the Breeders’ Cup Classic. I may have missed someone, but by my recollection, O’Brien is 9-0-1-1 with that move. This one seems different, and I am withholding judgment until closer to the race, but history tells me to wade in with caution, especially as a potential short priced favorite as City of Troy is getting bet fairly hard in the antepost market overseas as is 15/8 in many books as I write this.

Noting that there are numerous factors that help determine whether or not a horse can make the transition from turf to dirt that cannot be easily quantified, here is an analysis of TG data on the nine Classic starters from the O’Brien barn that retired after that race. Using the common definitions of Top, Pair, Off, and X for effort distribution (see below), of the nine O’Brien Breeders’ Cup Classic starters who retired after the race, it appears that O’Brien had the following: Top = 2 horses, Pair = 3 horses, Off = 2 horses, X = 2 horses. So, the performances have been all over the place in this relatively small sample size. What is interesting though is that if you focus on the time between starts, both tops and two of the pairs came from at least 42 days off. He did have one pair at 20 days and one off at 61 days. The three horses that were wheeled back after 14 days accounted for both of the X performances and one of the off performances. It seems at least in this sample, that having more time off makes it more likely that horses would run their races. In case you are wondering, City of Troy will be coming in off a 73 day layoff for the Classic.

Horse, Finish Position, Days Off Prior to Classic, Effort Distribution
Giant's Causeway, 2, 42, Top
Declaration of War, 3, 73, Top
Galileo, 6, 49, Pair
Black Minnaloushe, 10, 67, Pair
Duke of Marmalade, 9, 20, Pair
George Washington, 6, 61, Off
Oratorio, 11, 14, Off
Gleneagles, 8, 14, X
Churchill, 7, 14, X

Effort Distribution Definitions
Top: >1 faster than previous top
Pair: within 1 point of previous top
Off: >1 and <+4 worse than previous top
X: More than 4 points worse than previous top