Donnacha O'Brien
Fair A/E compares wins with a margin-stripped market expectation. Favourite-heavy samples — top yards, leading riders — naturally read a few points warm, so 1.05 means "beat the margin-free market read", not "the market underrates this by 5%".
Rode around 340 times a season, almost all on the flat, winning on 20% of them — beating the margin-free market read across the lifetime window (Fair A/E 1.11). Riding last-time-out winners the record reads 23% (298 rides). Rode mostly for A P O'Brien — 49% of rides in the window.
The record is strongest at Tipperary (28.8%, n=66), clear of the rider's 19.7% baseline. It is weakest at Ascot (3.1% over 64 rides) — the widest gap in the record. Rides on last-time-out winners have been a positive signal at 22.8% (n=298, Fair A/E 1.14), but in Group and Graded company the record reads poorly at 13.9% (n=431, Fair A/E 0.98). A P O'Brien supplied 49% of the rides and edges the rider's average (24.6% vs 19.7%, A/E 1.15) — the partnership beats the margin-free market read. The record read poorly off a 61-180-day break — 12.1% over 173 rides, 7.6pts below the baseline. 60 Group and Graded wins sit in the archive record — the biggest prize the rider has landed: the Dubai Duty Free Irish Derby at Curragh (Jun 2018, £855,000). The standout partner of the record was Waitingfortheday (IRE) — 6 wins from 13 rides together. Seasonally, the rider fired Jul–Aug.
Riding patterns
the angles behind the record · vs 19.7% baselineEach tile is the record in that situation vs the 19.7% baseline — descriptive splits with the sample always shown, for you to weigh. Tiles under 30 runs render muted. First rides are the first captured pairing of horse and rider; last-time-out winners are horses whose previous captured run was a win; claiming rides are runs where the rider carried a weight claim. Group / Graded covers pattern and listed races.
Notable angles
vs their own baselineRecord by conditions
same window as headerRace type
Going
Courses
Class
Market position
Distance
By season
Handicaps
Field size
Rows below n=30 are shown faded — a small sample is a fact, not a trend. Every figure carries its N.
Horses ridden
same window as header · most-raced firstBy month
strike by month, lifetimeRiding for
same window · biggest samples firstCareer highlights
lifetime archive, 2014→Sires of the horses ridden
progeny record · win % by ground and tripThe record
latest 50 of 2,030 · newest firstThe latest 50 of 2,030 archived rides, newest first. The full record runs from 23 July 2014 to 3 November 2019.
Drawn from the whole archive (2005 onwards), so it can include runs outside the window the header statistics cover. Non-runners are not listed. A finish shown in letters is a non-completion (F fell · UR unseated · PU pulled up · BD brought down).
Quick answers
- What is Donnacha O'Brien's strike rate?
- Donnacha O'Brien has won 400 of 2,030 rides since 2008, a strike rate of 19.7% (as at 6 November 2026). Figures are computed from our own results archive.
- Which course does Donnacha O'Brien do best at?
- Tipperary by strike rate: 19 wins from 66 rides (28.8%) since 2008. Read from the 15 courses with the most rides on the same basis, and only those with at least 30 — a small sample cannot top the list, and a rarely-visited course is not in the comparison.
- Which yard does Donnacha O'Brien ride most for?
- A P O'Brien, with 994 rides since 2008 — 49% of the total. That pairing has won 245 (24.6%).
- What is Donnacha O'Brien's Fair A/E?
- 1.11, from 2,025 rides with a computed fair probability since 2008. Fair A/E compares actual wins with a margin-stripped market expectation, so 1.00 is par: above it the wins came at bigger prices than the margin-free market implied, below it they did not.