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Jockey profile

Aileen O'Sullivan

142 rides in the lifetime window · 52 individual horses
As at 14 Nov 2026 · KTB archive: 2005–present, updated daily
Last ride 153 days ago
Last 5 seasons Lifetime (2014→)
from 1 Jan 2008 — the aggregate floor: every horse in the window has a complete captured career behind it
3–142
Wins / Runs
2.1%
Strike rate
n=142
16 (11%)
Placed
0.66
Fair A/E
n=142 · 0.53 incl. margin
−65.00
£1 level stake
n=142 at SP · −45.8%
£51,515
Prize money (window)
Strike by season
0%
KTB Rider Profile

Rides around 10 times a season, across both codes, winning on 2% of them — a touch below the margin-free market read across the lifetime window (Fair A/E 0.66). Rides mostly for S Michael Millar — 64% of rides in the window.

Deterministic profile computed from 142 archived runs (lifetime window) · updated 14 Nov 2026
KTB at a glance Fresh horses: 3.1% S Michael Millar: 2.2% from 91
The read

The market has consistently overbet claiming rides: 2.1% strike, Fair A/E 0.68 and −63.00 to a £1 stake over 140 rides — those runners underperform what the price implies. S Michael Millar supplies 64% of the rides and matches the rider's average almost exactly (2.2%, A/E 0.89). The rider also reads well off a 31-60-day break (6.7%, n=30) and over 1m5f – 2m (5.7%, n=35).

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

Riding patterns

the angles behind the record · vs 2.1% baseline
First ride on the horse · first captured pairing
0%−2.1
n=52 · A/E 0.00 · £1 −52.00
Last-time-out winners · previous run was a win
0%−2.1
n=4 · A/E 0.00 · £1 −4.00
Fresh horses · 61+ days off
3.1%+1.0
n=32 · A/E 1.34 · £1 +9.00
Claiming rides · riding with a claim
2.1%+0.0
n=140 · A/E 0.68 · £1 −63.00
Big fields · 14+ runners
0%−2.1
n=57 · A/E 0.00 · £1 −57.00
Group / Graded races · pattern & listed
0%−2.1
n=1 · A/E 0.00 · £1 −1.00

Each tile is the record in that situation vs the 2.1% 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 baseline
Off a 31-60-day break 6.7% vs 2.1% · n=30
Over 1m5f – 2m 5.7% vs 2.1% · n=35
In Chase races 4.8% vs 2.1% · n=42
On Good going 4.4% vs 2.1% · n=45
On first rides for the horse 0% vs 2.1% · n=52
In Hurdle races 0% vs 2.1% · n=45
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

Race type

TypeRWSR£1
Hurdle 45 0 0% −45.00
Chase 42 2 4.8% +28.00
Flat 40 0 0% −40.00
NH Flat 15 1 6.7% −8.00

Going

GoingRWSR£1
Good 45 2 4.4% +3.00
Soft 39 1 2.6% −10.00
Heavy 22 0 0% −22.00
Good to Soft 19 0 0% −19.00
Standard (AW) 16 0 0% −16.00
Good to Firm 1 0 0% −1.00

Courses

CourseRWSR£1
Downpatrick 22 1 4.5% +19.00
Dundalk (AW) 16 0 0% −16.00
Fairyhouse 15 1 6.7% −8.00
Down Royal 11 0 0% −11.00
Navan 9 0 0% −9.00
Wexford 7 0 0% −7.00
Clonmel 7 1 14.3% +22.00
Bellewstown 6 0 0% −6.00
Tipperary 5 0 0% −5.00
Kilbeggan 4 0 0% −4.00
Curragh 4 0 0% −4.00
Sligo 4 0 0% −4.00
Punchestown 4 0 0% −4.00
Cork 3 0 0% −3.00
Tramore 3 0 0% −3.00

Class

ClassRWSR£1
Class 4 3 0 0% −3.00
Class 5 3 0 0% −3.00
Class 1 1 0 0% −1.00
Class 2 1 0 0% −1.00

Market position

In the bettingRWSRA/E£1
2nd–3rd fav 7 0 0% 0.00 −7.00
4th–6th fav 22 1 4.5% 0.73 −15.00
7th+ in betting 113 2 1.8% 0.84 −43.00
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.

Jumping record

completion over obstacles · same window as header
82.8% completed · 87 obstacle rides (chases & hurdles)
CodeRCompFURPUBDOth
Chase 42 76.2% 1 2 7 0 0
Hurdle 45 88.9% 2 2 1 0 0
Chases and hurdles only — bumpers have no obstacles, so completion is not a question there. F fell · UR unseated rider · PU pulled up · BD brought down · Oth covers refusals, slip-ups, run-outs and the rare disqualification. Non-runners are excluded throughout. Rows under n=30 are shown faded. A descriptive record, not a tip.

Horses ridden

same window as header · most-raced first
HorseRWPlLast ran
San Martino (IRE) 14 0 2 29 Jun 24
Drimsree Lad (IRE) 14 0 2 16 Dec 23
Deo Bellator (IRE) 14 0 1 1 Oct 23
American Image (IRE) 7 1 3 22 Mar 21
Personal Shopper (GB) 7 0 3 26 Jul 18
Robin De Roost (IRE) 6 1 1 17 Aug 24
Carnival Spirit (IRE) 5 0 0 19 Nov 25
Hague Convention (IRE) 5 0 0 29 Nov 23
Nevada Rose (IRE) 5 0 0 26 Aug 19
Breagagh (IRE) 4 0 0 29 Aug 24
Samaritaine (GB) 4 0 0 25 Apr 22
Arctic Craft (IRE) 3 1 1 22 Nov 25
All 52 horses ridden in this window. 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.

By month

strike by month, lifetime
JFMAMJJASOND
0000060001800
A jumps rider: the season runs Oct–Apr. Muted months are small samples (under 30 runs) — read them with the caution they deserve.

Riding for

same window · biggest samples first
Main yardS Michael Millar
64% of all rides
2.2% SR · A/E 0.89
TrainerRWSR£1
S Michael Millar 91 2 2.2% −55.00
Muted rows are under 30 rides and sit behind "Show all".

Career highlights

lifetime archive, 2014→
3
Archived wins
£51,515
Prize money
2024
Best season · 2 wins
Robin De Roost (IRE) — Download The New Tote App Handicap Chase (0-109) Downpatrick · Jun 2024
£6,490
American Image (IRE) — Clonmel Handicap Chase Clonmel · Oct 2020
£6,490
Arctic Craft (IRE) — Morgan Fuels Supporting Louth GAA (Ladies Pro/Am) Flat Race Fairyhouse · Oct 2024
£5,900
Notable horses
American Image (IRE) Robin De Roost (IRE) Arctic Craft (IRE)

Sires of the horses ridden

progeny record · win % by ground and trip
Getaway (GER) 0% · 0–14
Progeny have won 11.3% of 11,047 runs since 2016 (1,034 horses). Strongest on Good to Firm going: 23.1% from 134.
Mr Combustible (IRE) 0% · 0–14
Progeny have won 6.9% of 638 runs since 2008 (53 horses).
The Gurkha (IRE) 0% · 0–14
Progeny have won 9.6% of 2,032 runs since 2020 (127 horses). Strongest on Good to Firm going: 13.7% from 183. Weakest on Heavy going: 2.9% from 105. Weakest over 2m1f – 2m4f (all codes): 6.3% from 112.
King's Theatre (IRE) 0% · 0–7
Progeny have won 14.4% of 12,129 runs since 2008 (746 horses). Weakest on Standard (AW) going: 4.8% from 125. Weakest over 1m2f – 1m4f (all codes): 7.9% from 203.
Lord Americo (IRE) 14.3% · 1–7
Progeny have won 7.8% of 2,189 runs since 2008 (237 horses).
Beneficial (GB) 0% · 0–6
Progeny have won 10.4% of 17,047 runs since 2008 (1,155 horses).
Top line: the rider'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 14 Nov 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 142 · newest first

The latest 50 of 142 archived rides, newest first. The full record runs from 28 August 2014 to 14 June 2026.

DateCourseHorseRaceFinishSP
14 Jun 26 Downpatrick Freeway (IRE)T: S Michael Millar Irish Stallion Farms EBF Mares (Pro/Am) Flat Race18f · Good · 8 ran 6th 80/1
19 Mar 26 Cork Mollys Star (IRE)T: P E Collins William Hill Each Way Extra Challenge Series Mares (Ladies Pro/Am) Flat Race16f · Yielding · 13 ran 6th 33/1
29 Nov 25 Fairyhouse Loughdoo (IRE)T: S Michael Millar Willie Elliott Memorial (Pro/Am) Flat Race16f · Yielding To Soft · 11 ran PU 100/1
22 Nov 25 Punchestown Arctic Craft (IRE)T: S Michael Millar Exhibit A Displays (Pro/Am) Flat Race16.5f · Soft To Heavy · 8 ran 7th 66/1
19 Nov 25 Dundalk (AW) Carnival Spirit (IRE)T: S Michael Millar Irishinjuredjockeys.com Nursery Handicap (0-60)7f · Standard · 14 ran 13th 40/1
01 Nov 25 Down Royal Paymelater (IRE)T: S Michael Millar Eventsec (Pro/Am) Flat Race17f · Yielding · 6 ran 4th 33/1
09 Oct 25 Tramore Paymelater (IRE)T: S Michael Millar Copper Coast (Ladies Pro/Am) Flat Race16f · Yielding · 8 ran 6th 18/1
29 Sep 25 Down Royal Carnival Spirit (IRE)T: S Michael Millar Molson Coors Beverage Company Nursery Handicap5f · Yielding · 12 ran 12th 100/1
27 Aug 25 Bellewstown Paymelater (IRE)T: S Michael Millar Tote.ie (Ladies Pro/Am) Flat Race17f · Good · 11 ran 4th 12/1
26 Aug 25 Bellewstown Carnival Spirit (IRE)T: S Michael Millar Irish EBF Auction Series Maiden5f · Good · 13 ran 12th 400/1
16 Aug 25 Curragh Carnival Spirit (IRE)T: S Michael Millar Irish European Breeders Fund Median Sires Series Maiden6f · Good · 19 ran 17th 300/1
07 Aug 25 Sligo Loughdoo (IRE)T: S Michael Millar Irish Stallion Farms EBF Mares (Pro/Am) Flat Race18.5f · Good · 9 ran 4th 25/1
05 Jul 25 Naas Carnival Spirit (IRE)T: S Michael Millar EMS Copiers Irish EBF Fillies Maiden5f · Good · 15 ran 13th 300/1
22 Apr 25 Fairyhouse Don't Talk (GER)T: Karl Thornton Fairyhouse Racecourse Ladies National Handicap Chase21f · Soft · 12 ran UR 12/1
21 Feb 25 Dundalk (AW) Glen Princess (IRE)T: Keith Henry Clarke SIS, Supporting Irish Racing Handicap8f · Standard · 11 ran 10th 100/1
17 Jan 25 Dundalk (AW) Jerandme (IRE)T: Kevin Prendergast Irishinjuredjockeys.com Rated Race16f · Standard · 6 ran 2nd 14/1
12 Oct 24 Fairyhouse Arctic Craft (IRE)T: S Michael Millar Morgan Fuels Supporting Louth GAA (Ladies Pro/Am) Flat Race16f · Good · 7 ran 1st 6/1
29 Aug 24 Navan Breagagh (IRE)T: S Michael Millar Racing Next At Navan On Saturday September 7th Handicap (47-65)14f · Good · 22 ran 17th 40/1
28 Aug 24 Bellewstown Arctic Craft (IRE)T: S Michael Millar Jim And Niall MacMahon Memorial (Ladies Pro/Am) Flat Race17f · Good · 12 ran 7th 66/1
17 Aug 24 Perth Robin De Roost (IRE)T: Thomas Gibney Every Race Live On Racing TV Handicap ChaseClass 5 · 24f · Good · 12 ran 8th 25/1

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 Aileen O'Sullivan's strike rate?
Aileen O'Sullivan has won 3 of 142 rides since 2008, a strike rate of 2.1% (as at 14 November 2026). Figures are computed from our own results archive.
Which yard does Aileen O'Sullivan ride most for?
S Michael Millar, with 91 rides since 2008 — 64% of the total. That pairing has won 2 (2.2%).
What is Aileen O'Sullivan's Fair A/E?
0.66, from 142 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.
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 14 November 2026, computed from our own results archive (2005 onwards; aggregates from 2008).