Why a big Derby team doesn't always equal big results for Aidan O'Brien

Aidan O'Brien will saddle seven runners and more than half the field in the Investec Derby at Epsom on Saturday as he bids for a record-equalling seventh win in the Classic.

It's not the most runners O'Brien has saddled in the Derby – he ran eight in the contest won by the Peter Chapple-Hyam-trained Authorized in 2007.

But it begs the question: does the size of O'Brien's Derby team have much impact on his success?

We crunched the numbers to take a look, with some interesting results.

Galileo was the first and only Derby winner of O'Brien's to not face stablemates at EpsomCredit: Edward Whitaker

Multiple runners the norm for O'Brien – but better record with fewer

In the last 20 Derbys, O'Brien has been responsible for at least one runner every year, which is not a surprise. After all, the last time O'Brien did not have a runner in any British Classic was the Oaks won by Love Divine in 2000.

He has run three runners or more in 15 of the last 20 Derbys and four runners or more in 11 of the 20.

However, only two of his six wins in the race have come when he has saddled four or more runners. O'Brien has therefore had a better success rate in the Derby when running three or fewer runners.

Aidan O'Brien in the Derby (1999-2018)

1 runner 4 times – 1 winner
2 runners 1 time – 1 winner
3 runners 4 times – 2 winners
4 runners 5 times – 1 winner
5 runners 3 times – 0 winners
6 runners 2 times – 1 winner
8 runners 1 time – 0 winners

O'Brien's first Derby winner was Galileo and it is the only time the trainer has won with his only runner in the race. He has been represented by only one runner just once since, when Meath was a well-beaten last in North Light's Derby in 2004.

Most trainers know if they have a Derby horse

There used to be an old saying that if you thought you had more than one Derby horse you didn't have one. Basically, if you had a potential Derby winner in your ranks they would stand out.

Results indicate some truth in this as 14 of the last 20 Derby winners were the only representative from their yard, including Masar last year.

Of the remaining six, five were trained by Aidan O'Brien and the other by John Gosden, who watched Golden Horn beat stablemate Jack Hobbs four years ago.

However, there are signs of a transition. Five of the last seven Derbys have been won by a trainer with more than one runner in the race, which is very much against the overall 20-year trend.

How do I decide between O'Brien's seven?

Impressive Chester Vase winner Sir Dragonet, supplemented for £85,000 on Monday, is favourite for the Derby and the shortest-priced of O'Brien's seven runners.

Interestingly, O'Brien's two Derby wins with a team of four or more runners – Ruler Of The World (2013) and Wings Of Eagles (2017) – were not won by the shortest-priced contender.

Wings Of Eagles (left of picture) was not one of O'Brien's fancied runners in the 2017 DerbyCredit: Edward Whitaker

Battle Of Marengo was 11-2 when fourth in 7-1 shot Ruler Of The World's Derby win, while 40-1 shock winner Wings Of Eagles was the fifth-biggest price of O'Brien's six when he prevailed under Padraig Beggy.

It is also a trend reflected in the other British Classics, with the exception of the St Leger, when O'Brien runs a big team.

Forever Together (7-1) and Was (20-1) were not first choice for their Oaks successes, while Rock Of Gibraltar (9-1) denied favourite and stablemate Hawk Wing in the 2,000 Guineas. Hermosa (14-1) added to the trend when winning the 1,000 Guineas at Newmarket this month.

History suggests Sir Dragonet is far from certain to lead home O'Brien's big contingent and, even then, remember the 2007 Derby – a big team does not guarantee a big result at Epsom. Sometimes only one horse is enough.

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