Cheltenham - The Ground Rules

In the build-up to the festival, we hear some clichéd “rules” and guidelines as to what you should and shouldn’t back – people telling you not to back the favourite, not to back top weight in handicaps, etc. We’ve outlined two of the ground rules at Cheltenham and looked into why they should be followed.

1. Don’t Back The Girls Against The Boys

Of the 257 festival races in the last 10 years, 111 have included runners of both sexes, and so it’s these 111 races that provide the basis for our investigation.

1. So, in the 111 races, there was a total of 2,100 males running and 168 females, all competing for the 111 wins and 391 total places (including wins) which were up for grabs. In total, the 111 winning spots were taken up by 106 males and 5 females.

So, fact number one: there were approximately 5.4 times more males than females in the races, and they won 21.2 times more races.

2. 92.6% of the total field were males, as were 92.8% of the total places – so, when we look at the data like this we see horses of each sex performing exactly as we would have expected them to. Likewise, 7.4% of the total field were female, as were 7.2% of the total places.

Even wonder-mare Annie Power came up short against a
male competitor in last year's World Hurdle

3. The final way we look at this is a bit more complicated, but gives us a very accurate idea of how horses performed. Firstly, we look at each runner’s odds, and give it a number of probability based on said odds. A 10/1 shot’s expectancy/probability of winning is 0.09, an evens favourite is 0.5.

Basically, we're going to add all of these “expectancies” together and divide the total by the amount of winners. The males' final figure of actual wins/expected wins is 0.81. When we do the same with the females, our final figure is 0.53.

It may be worth noting that in the one case where the females don’t greatly underperform in our statistics, we’re taking places into consideration. Therefore, it might be worth watching the girls if you want an each-way bet, but when it comes to picking a winner, it’s all about the boys.

Annie Power losing the World Hurdle last year as 11/8 favourite was a high-profile case of a talented female horse losing at the festival. There have been plenty more though - Ping Pong Sivola was the 13/2 favourite in what is now the Byrne Group Plate in 2009, My Petra the 3/1 favourite in the 2008 Grand Annual, Luanos the 7/2 favourite in the 2007 Triumph, and Amaretto Rose the 2/1 favourite in the 2007 Supreme. These were all the female clear favourites since 2007, and their form reads 30222 – they can place, but the girls just never seem to have what it takes to win.

2. Don’t Back 11yos+

1. We’ll look at this in much the same way – 112 races in the last 10 festivals have featured at least one horse aged 11 or older, with 2,139 total runners in these races and 344 total places up for grabs. 16% of the runners in these races were actually aged 11+ (344 runners), and this 16% of runners managed to win about 4.5% of the races (5 races).

Hurricane Fly bids to win the Champion Hurdle aged 11 in 2015

2. Furthermore, this 16% of runners managed to take up 13.1% of places – a better record than they had in terms of winners, but a slight underperformance all the same.

3. If we look at the data in the same way as we did in part one (actual amount of wins/expected amount of wins) we come up with a minute 0.29. This means that not only did the horses aged 11+ fail to win very much in the last 10 years, they had, according to the bookmaker's odds, been well fancied to do a lot better than they did. 

We have to look back to 2010 to find the last time a horse aged older than 10 won at the festival, and this was Alfie Sherrin, a 12yo winning the Glenfarclas over 3m 7f. Before that it was 2008 and Mister McGoldrick winning what is now the Byrne Group Plate as an 11yo over 2m 4½f. Before that, 2006 when Native Jack was 12 when he won the Glenfarclas. In 2005, Moscow Flyer won the Champion Chase as an 11yo and Spot Thedifference won the Glenfarclas aged 12.

Notice anything? Yep, the Glenfarclas. So, apparently we need to make a slight exception to this ground rule in that the older horses have performed extremely well in the Glenfarclas.

With both the females and the over 11's, their place records aren't as bad as is often suggested. Therefore, if there was an each-way long shot I wanted to back at the festival, I wouldn't necessarily be put off by either of these factors. However, the statistics clearly show that females and over 11's find it difficult to win at Prestbury Park in March.