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Trainer profile

Aidan O'Brien

3,214 runners in the last 5 seasons · 564 individual horses
As at 20 Oct 2026 · KTB archive: 2005–present, updated daily
Non-runners: 5.9% of 746 declared in the last 365 days, counting all recorded withdrawals, including reserves. For context, a typical day across all racing ends with about 6.5% withdrawn (middle half 5.3–8.1% over 364 racing days). As at 20 Oct 2026.
Last runner yesterday 100% of runners on the flat
Last 5 seasons Lifetime (2008→)
from 1 Jan 2022
700–3,214
Wins / Runs
21.8%
Strike rate
n=3,214
1,430 (45%)
Placed
1.09
Fair A/E
n=3,204 · 0.92 incl. margin
−622.81
£1 level stake
n=3,214 at SP · −19.4%
£77.2m
Prize money (window)
Strike by season
18.2%
KTB Yard Profile

Sends out around 640 runners a season, almost all on the flat, winning with 22% of them — beating the margin-free market read across five seasons (Fair A/E 1.09). The yard is quiet just now — 11 winners in the last fortnight, below its own baseline.

Deterministic profile computed from 3,214 archived runs (last 5 seasons) · updated 20 Oct 2026
KTB at a glance Fires Mar–May 46.2% when favourite R L Moore: 31.7% from 1,121 Sends off the favourite in 28% of races
The read

The record is strongest at Chester (60.6%, n=33), clear of the yard's 21.8% baseline. It is weakest at Longchamp (FR) (10.9% over 128 runners) — the widest gap in the record. Runners with a claiming rider up have been a poor signal at 14% (n=272, Fair A/E 1.02). Right now the yard is in a quiet spell: 11 from 60 runners in the last 14 days (18.3%, 3.5pts below the 21.8% baseline). R L Moore rides 35% of the entries and beats the yard's average (31.7% vs 21.8%, A/E 1.12) — the partnership beats the margin-free market read. The record reads poorly off a 0-7-day break — 4.5% over 66 runners, 17.3pts below the baseline. 1,115 Group and Graded wins sit in the archive record — the biggest prize the yard has landed: the Qatar Prix de l'Arc de Triomphe at Chantilly (FR) (Oct 2016, £2,100,735). The stable star of the record: Kyprios (IRE) — 17 wins from 21 runs for the yard. Seasonally, the yard fires Mar–May.

Written from the figures on this page — every claim carries its sample. Descriptive, not a tip.

Yard patterns

the angles behind the record · vs 21.8% baseline
Fresh · 61+ days off
21.5%−0.3
n=516 · A/E 1.03 · £1 −120.12
New recruits · first run for the yard
0%−21.8
n=1 · A/E 0.00 · £1 −1.00
Debutants · first career start
17.8%−4.0
n=505 · A/E 1.06 · £1 −87.16
First-time headgear · true-first definition
16.3%−5.5
n=239 · A/E 1.14 · £1 −57.22
Headgear returns · back on after a bare run
20%−1.8
n=25 · A/E 1.41 · £1 +3.75
When favourite
46.2%
n=910 · A/E 1.13 · £1 −34.71
Claiming riders · a claimer in the saddle
14%−7.8
n=272 · A/E 1.02 · £1 −46.14
Group / Graded races · pattern & listed
19%−2.8
n=1,621 · A/E 1.03 · £1 −468.60

Each tile is the record in that situation vs the 21.8% baseline — descriptive splits with the sample always shown, not tips. Tiles under 30 runs render muted. Headgear figures use the true-first definition (first gear appearance in the captured career); returns are gear back on after a bare run. Claiming riders are runs where the booked rider carried a weight claim. Group / Graded covers pattern and listed races.

Notable angles

vs their own baseline
At Chester 60.6% vs 21.8% · n=33
Off a 0-7-day break 4.5% vs 21.8% · n=66
With Gavin Ryan 3.9% vs 21.8% · n=51
With R L Moore 31.7% vs 21.8% · n=1,121
With Dylan Browne McMonagle 3.1% vs 21.8% · n=32
At Longchamp (FR) 10.9% vs 21.8% · n=128
Descriptive splits ranked by divergence × sample — insight, not instruction. Every angle carries its N; nothing under 30 runs qualifies. Rows within 2pts of the baseline appear only when the market-relative read (Fair A/E) diverges, and show it.

Record by conditions

same window as header

Going

GoingRWSR£1
Good 1,231 312 25.3% −88.99
Soft 771 153 19.8% −188.11
Good to Firm 386 73 18.9% −113.37
Good to Soft 361 61 16.9% −131.71
Heavy 301 62 20.6% −51.04
Standard (AW) 164 39 23.8% −49.59

Courses

CourseRWSR£1
Curragh 768 168 21.9% −187.72
Leopardstown 451 101 22.4% −59.97
Naas 235 65 27.7% −1.06
Ascot 212 31 14.6% −61.84
Dundalk (AW) 161 39 24.2% −46.59
Navan 139 43 30.9% +26.67
Longchamp (FR) 128 14 10.9% −58.00
Gowran Park 106 25 23.6% −17.90
Cork 106 16 15.1% −37.75
Newmarket 98 15 15.3% −30.14
Galway 89 19 21.3% −18.18
York 78 13 16.7% −24.76
Tipperary 59 13 22% −17.55
Killarney 57 14 24.6% +5.45
Doncaster 51 7 13.7% −20.90

Class

ClassRWSR£1
Class 1 1,622 308 19% −469.60
Class 2 76 10 13.2% −34.80
Class 3 9 4 44.4% +5.38
Class 4 7 2 28.6% −3.65

Market position

In the bettingRWSRA/E£1
Favourite 963 430 44.7% 1.12 −52.21
2nd–3rd fav 1,008 207 20.5% 1.17 −43.30
4th–6th fav 806 51 6.3% 0.78 −306.70
7th+ in betting 437 12 2.7% 0.86 −220.60
Fair A/E per band is the tell: near 1.00 the market had it priced right; well above, the wins came where the market didn't expect them.

Rows below n=30 are shown faded — a small sample is a fact, not a trend. Every figure carries its N.

Horses trained

same window as header · most-raced first
HorseRWPlLast ran
Queenstown (IRE) 19 2 12 17 Oct 26
Illinois (IRE) 19 5 12 21 Aug 26
Continuous (JPN) 18 5 7 26 Jul 25
Kyprios (IRE) 17 15 16 16 May 25
Mississippi River (IRE) 16 3 10 17 Jun 26
Emily Dickinson (IRE) 16 4 6 30 Sep 23
Lambourn (IRE) 15 6 7 12 Sep 26
Exactly (IRE) 15 2 7 18 Oct 25
Los Angeles (IRE) 15 7 9 5 Oct 25
Aesop's Fables (IRE) 15 3 7 6 Oct 24
Hans Andersen (GB)then Veronika Jandova 15 3 5 14 Sep 24
Minnie Hauk (IRE) 14 7 11 17 Oct 26
Showing the 60 most-raced of the 564 horses sent out in this window — each ran at least 11 times. Horses with fewer runs aren't listed; search finds any horse since 2005. Runs, wins and places only: a strike rate or a return on a handful of runs is noise, so none is quoted per horse — each horse's full record is on its own page.
Where they came from · where they went next

Of the 60 horses listed, none arrived from another yard in our archive — all 60 had their first archived run here.

2 have since run for another yard; 58 have no later run for another yard in our archive.

Read from each listed horse's whole archived career (2005 onwards), not only this window, and counted over the horses listed above, not the whole string. “First archived run” means our archive holds nothing earlier, not that the horse was unraced. A horse with no later run elsewhere may still be here, be off the track, or have run somewhere our archive does not cover — none of that is asserted.

Current form

significance-gated

Last 14 days

Quiet spell
11 from 60 18.3% · −3.5pts vs baseline
Last 14 days18.3%
5-season base21.8%
Shown only when the 14-day window is large enough to mean anything (n≥15). A cold run renders the same card with a quiet badge — never hidden.

When the yard fires

strike by month, 5 seasons
JFMAMJJASOND
··2723272220261820130
A flat yard: the season runs Mar–Oct. Muted months are small samples (under 30 runs) — read them with the caution they deserve.

Jockey bookings

same window · biggest samples first
Go-to riderR L Moore
35% of all rides
31.7% SR · A/E 1.12
RiderRWSR£1
R L Moore 1,121 355 31.7% −103.12
W. M. Lordan 918 180 19.6% −174.82
Seamie Heffernan 313 63 20.1% −44.79
Jack Cleary 218 29 13.3% −64.10
R. P. Whelan 115 15 13% −39.78
C. Soumillon 84 18 21.4% +9.45
Declan McDonogh 53 5 9.4% −24.93
Gavin Ryan 51 2 3.9% −44.84
Killian Hennessy 39 7 17.9% −6.67
Dylan Browne McMonagle 32 1 3.1% −30.71
Muted rows are under 30 rides and sit behind "Show all".

Career highlights

lifetime archive, 2005→
2,812
Archived wins
1,115
Pattern / graded wins
£244.8m
Prize money
2018
Best season · 179 wins
In our archive from its very first year (2005), so this career almost certainly began earlier than our record does. The figures above count 2005 onwards only — what the archive holds, not a full-career total. This card is the full archive census (2005→); the statistics in the header aggregate from 2008 — the floor that guarantees every horse a complete captured career — so this card can legitimately show more wins than the header.
Found (IRE) — Qatar Prix de l'Arc de Triomphe (3yo+ No Geldings) (Turf) Chantilly (FR) · Oct 2016 · Group 1
£2,100,735
Christmas Day (IRE) — Betfred Derby (Group 1) Epsom Downs · Jun 2026 · Group 1
£1,000,000
Wings Of Eagles (FR) — Investec Derby (Group 1) Epsom Downs · Jun 2017 · Group 1
£921,538
Notable horses
Kyprios (IRE) Fame And Glory (GB) Order Of St George (IRE) Magical (IRE) Yeats (IRE) Dylan Thomas (IRE)

Sires in the string

progeny record · win % by ground and trip
Chanting (IRE) 21.5% · 125–581
Progeny have won 14.5% of 18,190 runs since 2008 (1,776 horses). Strongest over 6f – 7f (all codes): 18.2% from 1,383. Weakest over 2m5f – 3m (all codes): 9.3% from 888.
Wootton Bassett (GB) 22.3% · 110–494
Progeny have won 13.1% of 5,628 runs since 2008 (788 horses). Strongest at trips under 6f (all codes): 16.1% from 161.
No Nay Never (USA) 21.9% · 96–439
Progeny have won 12.1% of 6,307 runs since 2008 (704 horses). Weakest on Good to Soft going: 9% from 612. Weakest over 1m5f – 2m (all codes): 7.6% from 185.
Frankel (GB) 23.9% · 60–251
Progeny have won 18% of 7,495 runs since 2008 (873 horses). Weakest on Heavy going: 12.3% from 324. Weakest over 2m1f – 2m4f (all codes): 12.4% from 267.
Dubawi (IRE) 19.9% · 46–231
Progeny have won 18.4% of 12,933 runs since 2008 (1,520 horses). Weakest at trips under 6f (all codes): 9.8% from 429.
Camelot (GB) 20.2% · 40–198
Progeny have won 11.7% of 7,675 runs since 2008 (752 horses).
Top line: the yard's own record with each sire's runners (win %, wins–runs), same window as the header; faded under 30 runs. Beneath it: every run by that sire's progeny in our archive since 2008, as at 20 Oct 2026 — what they have done, not a forecast. A going or a distance is named only where at least 100 progeny runs sit 3 or more points from the sire's own win rate. Distance bands cover Flat and jumps together.

The record

latest 50 of 14,184 · newest first

The latest 50 of 14,184 archived runners, newest first. The full record runs from 20 March 2005 to 19 October 2026.

DateCourseHorseRaceFinishSP
19 Oct 26 Gowran Park (IRE) Conclusive (IRE)J: Gavin Ryan Irish Stallion Farms EBF Maiden8.5f · Soft · 14 ran 10th 11/1
19 Oct 26 Gowran Park (IRE) Heart Of Fire (IRE)J: Paddy Harnett Irish Stallion Farms EBF Maiden8.5f · Soft · 14 ran 8th 6/1
19 Oct 26 Gowran Park (IRE) Paraguay (USA)J: Jack Cleary Irish Stallion Farms EBF Maiden8.5f · Soft · 14 ran 2nd 9/2
18 Oct 26 Leopardstown (IRE) Purely (IRE)J: W. M. Lordan Watch Every Irish Race Live On Racing TV Handicap7f · Good · 14 ran 4th 10/1
18 Oct 26 Leopardstown (IRE) Come What May (IRE)J: W. M. Lordan Trigo Stakes (Listed)Class 1 · 10f · Good · 9 ran 1st 4/6F
18 Oct 26 Leopardstown (IRE) Lewis Carroll (IRE)J: W. M. Lordan Bahrain Turf Club Knockaire Stakes (Listed)Class 1 · 8.5f · Good · 7 ran 2nd 20/1
18 Oct 26 Leopardstown (IRE) King Of Sparta (IRE)J: W. M. Lordan Leopardstown Golf, Padel And Range Maiden9f · Good · 15 ran 7th 3/1
17 Oct 26 Leopardstown (IRE) City Of Gold (GB)J: W. M. Lordan Irish Stallion Farms EBF Nursery Handicap8.5f · Good · 7 ran 1st 13/8F
17 Oct 26 Leopardstown (IRE) Walnut Cove (USA)J: Paddy Harnett Irish Stallion Farms EBF (C & G) Maiden7f · Good · 12 ran 11th 33/1
17 Oct 26 Leopardstown (IRE) Imposing (IRE)J: Jack Cleary Irish Stallion Farms EBF (C & G) Maiden7f · Good · 12 ran 2nd 22/1
17 Oct 26 Leopardstown (IRE) Accumulation (IRE)J: W. M. Lordan Irish Stallion Farms EBF (C & G) Maiden7f · Good · 12 ran 1st 5/2
17 Oct 26 Leopardstown (IRE) Capability Brown (IRE)J: W. M. Lordan Mongey Communications Killavullan Stakes (Group 3)Class 1 · 7f · Good · 6 ran 1st 100/30
17 Oct 26 Ascot Constitution River (FR)J: Ryan Moore Qatar Racing Champion Stakes (Group 1)Class 1 · 10f · Good · 6 ran 5th 9/2
17 Oct 26 Leopardstown (IRE) Anymore (IRE)J: Jack Cleary Irish Stallion Farms EBF Laidlaw Cup Fillies Maiden7f · Good · 13 ran 8th 22/1
17 Oct 26 Leopardstown (IRE) Snowing (IRE)J: W. M. Lordan Irish Stallion Farms EBF Laidlaw Cup Fillies Maiden7f · Good · 13 ran 1st 5/4F
17 Oct 26 Ascot Hawk Mountain (IRE)J: Colin Keane Queen Elizabeth II Stakes (Sponsored By Qatar Racing) (Group 1)Class 1 · 8f · Good · 11 ran 11th 33/1
17 Oct 26 Ascot Gstaad (GB)J: Ryan Moore Queen Elizabeth II Stakes (Sponsored By Qatar Racing) (Group 1)Class 1 · 8f · Good · 11 ran 8th 7/4F
17 Oct 26 Leopardstown (IRE) Albany County (IRE)J: Jack Cleary Mongey Communications Eyrefield Stakes (Group 3)Class 1 · 9f · Good · 6 ran 5th 9/1
17 Oct 26 Leopardstown (IRE) Wall Street (GB)J: W. M. Lordan Mongey Communications Eyrefield Stakes (Group 3)Class 1 · 9f · Good · 6 ran 1st 4/7F
17 Oct 26 Ascot Sugar Island (IRE)J: C. Soumillon Qatar Racing British Champions Fillies & Mares Stakes (Group 1)Class 1 · 12f · Good · 12 ran 4th 150/1

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 Aidan O'Brien's strike rate?
Aidan O'Brien has won 700 of 3,214 runners since 2022, a strike rate of 21.8% (as at 20 October 2026). Figures are computed from our own results archive.
Which course does Aidan O'Brien do best at?
Navan by strike rate: 43 wins from 139 runners (30.9%) since 2022. Read from the 15 courses with the most runners 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.
Who rides most for Aidan O'Brien?
R L Moore, with 1,121 runners since 2022 — 35% of the total. That pairing has won 355 (31.7%).
Is Aidan O'Brien in form?
In the last 14 days: 60 runners, 11 winners, a strike rate of 18.3%. That is below the baseline of 21.8% since 2022.
What is Aidan O'Brien's Fair A/E?
1.09, from 3,204 runners with a computed fair probability since 2022. 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.
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%". Three sample sizes are reported and never blended: runs (n), the ROI basis (n at SP), and the fair-A/E basis (n with a computed fair probability).

Strike rate is wins over all runs (n). ROI is £1 level stakes at SP over runs with a parseable price (n at SP). Fair A/E is wins over margin-stripped market expectation, over runs with a computed fair probability (n fair). The three Ns can legitimately differ and are always shown. Figures as at 20 October 2026, computed from our own results archive (2005 onwards; aggregates from 2008).