Aintree, the Grand National and fallers

07/04/2017 | By | Reply More

If there is one thing Aintree is known for it is spectacular fallers. In 2011 British racing yielded to public opinion and changed the fences at Aintree. The idea was to stop more fallers and serious injuries to horses. Did that happen? Will it happen? What the key factors behind a faller in a race?

Source data

To answer all the questions I took a look at half a million horses that raced around the various jumps races over the last ten years or so. I couldn’t have done this with the excellent and without the help of Chris who runs that site. So many thanks for his help!

Don’t forget the humans!

One thing annoys me about the horse welfare debate, is the human element or the lack of it I should say. Each year I contribute to the injured jockey’s fund, I feel obligated. Yes, I know they choose to do it, but there are few sports where you can be killed or seriously injured by participating. So Jockey’s deserve, but get little say or credit in these key matters. When one is seriously injured, there doesn’t seem much interest or continued support. Certainly not as much as the anti-racing lobbyists seem to generate when a horse dies.

More horses fall at Aintree

First off, let’s get the nasty stuff out of the way. It’s true that a lot of horses fall at Aintree. At Aintree 6.5% of horses never make it around the course. That’s 2.5% more than the next nearest course and about twice the normal level or fallers, but we know it’s challenging, that is what makes Aintree. However like all statistics that tells a lie, we will review it at the bottom of this post. What we need to know is if some of the characteristics of the great race are the cause?


The Grand National is run over a distance of over 4m, that’s a long race. Does that have an impact?

If you look at distance, we see that as horses get fatigued they tend to fall more often. Something run over 4miles is likely to fall more often than two miles, about twice as often. However, I noticed that once you pass three miles in distance, it doesn’t seem to  make a great deal of difference. So where do you cut off? You can’t really. It’s obvious that something will tire over time, but even if you shortened the length to three miles it wouldn’t really make much difference.

Field size

Here comes our first surprise. As percentage of field size, three runner fields  are much more likely to have a faller than larger fields. The correlation is very clear, more runners equal less fallers. This seems pretty illogical, but it’s true. As a percentage of field size you get less fallers with big fields. I can’t immediately explain this, but it’s a fact. So reducing the field size of the national, wouldn’t reduce fallers.

Perhaps it is the rhythm of the horses over jumps that allows subsequent jumpers to judge their timing a bit better?


When I did this research, going was the primary thing I was interested in. I felt there had to be a strong correlation between going and fallers. You can imagine heavy going, tired horses, trying to jump some fence but just being unable to do so. I was wrong….

It turns out that if the going is heavy, then the horse is traveling slower and more able to accurately time a jump. The worst ground for fallers is firm ground. On firm ground they travel faster into the fence, tend to get the timing wrong and are more likely to fall. This was a complete surprise for me. But totally vindicates horse racing’s general view that lower fences increase speed and are more likley to produce a faller. The statistics I have collected would appear to back this up.

Changes at Aintree

Given all the above, I thought I would look at whether all the many changes that have been made an Aintree have had an impact. It turns out they have. The graphic shows a steep decline in the number of fallers. So which ever way you look at it, take any negative comments on the National today with a pinch of salt and now, some logic to back it up.

Fallers at Aintree

Tags: , , , , ,

Category: Trading strategies

About the Author ()

I left a good job in the consumer technology industry to go a trade on Betfair for a living way back in June 2000. I've been here ever since pushing very boundaries of what's possible on betting exchanges and loved every minute of it.

Leave a Reply

You must be logged in to post a comment.