What Influences a Horse’s Odds?

A comprehensive guide explaining the factors that influence a horse's odds and starting price. From horse-specific factors to environmental ones.

In this article we will be touching on the many factors affecting a horse's odds, and what you may need to look out for when placing bets on horse racing.

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One of the most obvious factors that affects a horse's odds is the horse itself. this is broken down into multiple sub-factors, which we will cover below.

Form of the horse

Firstly, a horses form is a record of its previous results. Form is recorded in a form book on a race card, and is presented as a number for where they placed in their last race e.g. the number "1" means they won their last race, "PU" means "Pulled Up". from this form, bookmakers begin to price up their odds of the horses perceived chance to win a race. the performances of horses that the horse in question has either beaten or lost to will impact the odds of the horse, either bolstering its chances or diminishing them based on their last run.

Shape in the parade ring

The shape of a horse in the parade ring can sometimes give pointers to the mental and physical state of the horse. Things like limpingagitation and a poor handler relationship could all negatively affect the horse's odds as it's shows they are physically, and/or mentally, unfit to win the race. This is more opinion based than factual. On the contrary, if a horse looks muscularstrong and focused this may result in the odds being shorter. Punters will see that it is race-ready, potentially leading to more bets on the horse. Of all, this is considered less influential than the other factors.

The horse's last race

Of a horses form, the last race is arguably the most important factor as it shows their most recent accomplishments, be that good or bad. If a horse performed poorly in its last race, for example it was pulled up or fell, their odds are likely to be far longer, whereas if the horse won its last race comfortably, or even was narrowly beaten, the odds for their next race will likely be shorter as a result.


Reputation boils down to the horse itself and its running and jumping style from previous performances. Some horses will begin a race as a front runner, accrue a lead of multiple lengths, and begin to slowly lose stamina and eventually end up with the main pack nearing the end of the race. On the other, hand some horses like to sit nearer the back of the field to conserve energy, and will use this energy to end the race in a sprint. These particular running styles suit some tracks better than others, therefore having an effect on the odds of the horse.

The jumping style of a horse will also affect the horse's odds as some horses make mistakes more often than others. If the horse has a reputation to jump to the right on a left handed track, it shows an affinity to the right hand side and therefore will affect its odds if running at a left handed track. The obvious aspect of reputation is whether a horse is seemingly "unbeatable". If it is yet to lose a race, its odds will be very short as no other horse has proved better than it.

Equipment changes

In horse racing you will sometimes see some added equipment on the horse to try and improve its concentration. Equipment such as visors, cheek pieces and blinkers can have a revolutionary effect on a horse using it for the first time, and seeing a horse completely reverse its form from losing to winning is not uncommon in those sporting new equipment. First time headgear may shorten the odds of a horse due to the possibility of a stark improvement.

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Most influential factors affecting a horse's odds.

Some of the other most prevalent factors for a horse's odds are the people surrounding it, the spectators, those commenting on it and those placing bets. We will cover these factors below.

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The jockey

The jockey has a significant role in the horses odds in a race. Some jockeys have good records on certain horses and tracks, especially well known jockeys such as Paul Townend. He is 2021's favourite to be Cheltenham's top jockey, meaning the horses he is riding may go off shorter than if another jockey was to ride them. That said, all jockeys have the capability to ride a horse to victory and although the jockey plays a big part in the horses odds, the horse itself has to be willing to win the race. 

The trainer

Certain trainers are feared in today's racing from having a fierce record of winners. The names Paul Nicholls and Nicky Henderson top the list for the last few years in the UK due to having a large tally of winning horses in recent times. Horses trained by top trainers are often favorites for big races as they hold good records of certain courses, meaning they are likely near the top of the betting in big events. One thing to look out for is previous wins by trainers in a certain race. An example of this is Willie Mullins, the most prolific trainer in history at cheltenham, training an unmatched 73 winners, and Mullins' horses are often favourites at the festival because of this. A trainers current form is just as important, if not more important, than past successes. It is important for a trainers yard as a whole to perform well and if a trainer is in a fine vein of form, other runners of theirs will likely be at shorter odds.

The owner

Some owners have become incredibly popular among the racing public and their horse's odds seem to be shortened as a result. Other owners become renowned for winning handicaps, and plotting to win races way into the future. JP McManus has a reputation for winning some big handicap races, and because of this, his horses are often favourites in big handicaps particularly at the Cheltenham festival.

The commentators

Especially in televised horse racing, the commentators and pundits will have an opinion or fancy on a horse in the race. People watching at home will listen to their input and potentially begin to place bets on the mentioned horse. If enough bets are placed by viewers at home it can result in a shortening of price before the race. This can also work the other way, because if a pundit believes a horse has little chance, they will not get backed as much in the market leading to their price drifting out before the off. Commentators and pundits are usually fairly well informed, but as we know horse racing can go any which way when the race begins.

The tipsters

If a popular tipster has posted a tip to bet on a particular horse, it is likely to receive widespread market support and the bookmakers will in turn adjust the odds accordingly. Back in the days, tipsters made predictions in newspapers, whereas nowadays you will find influential tipsters on Twitter, message boards, reddit, and on horse racing betting sites themselves. There is a wealth of pseudo self-proclaimed experts.

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The race itself can impact a horse's odds considerably for a number of reasons, which we will discuss below:

Type of race

Horse Racing in the UK and Ireland is run at different levels, based on ability from Class 1-6. In Flat racing, Class 1 is split from the best in Group 1 down to Group 3 and Listed races. in National Hunt Racing the classes are the same but Class 1 is divided into Grade 1,2,3 and listed. The class of race a horse is running in would also affect their odds; should they be stepping up in class their odds are likely to be longer and Vice-Versa.

The distance that a race is over will have a huge impact on a horse's odds. If the trip is not optimum for a horse, or they are inexperienced at a certain race trip, their odds may be longer unless visually they previously appeared to be in need of a change of trip.

In horse racing there are handicap races, where horses carry varying weights based on their official rating and perceived ability. Depending on the amount of weight a horse is carrying in a handicap, their odds will be affected either positively or negatively depending on whether punters believe that they are well handicapped or not.

Track conditions

The track conditions have can impact a horse's odds for a number of reasons. Firstly, the ground or the going is vitally important and is recorded as Firm, Good, Soft, Heavy and increments between. Certain horses show to perform far better on particular ground- meaning the weather before a race and the ground becomes pivotal to their chances.

Secondly, certain horses (particularly in National Hunt Jumps Racing) perform far better on either a Left or Right-Handed track which is another factor to consider when betting on a horse and something that affects the odds.

There are a few other factors that affect the odds based on the track and course itself; how sharp the course is, whether the course has any hills or inclines and the position of obstacles are some important ones.


A race where one or multiple horses are withdrawn and become non-runners would mean that remaining horses have a greater chance of winning, therefore their odds will shorten. On the day of a race following non-runners being declared, bets on other horses will be subject to a Rule 4 deduction which means their returns will be reduced by a factor according to the increased chance of them winning.

Bookmakers' starting prices

The final odds of a horse are largely similar to the bookmakers initial prices offered. Bookmakers would calculate their perceived chances of winning for each horse and create odds from this. These odds will change according to the amount of money placed on each horse and due to the other factors that we have listed, but the final Start Price of a horse tends not to be too dissimilar from the Bookmakers initial price.

Form of other runners

A horse's odds are affected by the odds of other horses in the race- their competitors. Each horse's odds have been affected by their form and, as a result, if the horse in question is in a field against horses with poor form, the horse in question is likely to have relatively short odds, and vice versa.

Herd mentality

Something that is commonplace in horse racing is rumors and bet tipping. This often leads to a herd mentality where if one runner has been popular and backed by a large number of punters, then it is tipped to their friends. Those individuals may tell more people that it is a great bet, and the cycle repeats. This would lead to the horse's odds shortening considerably as bookmakers liability against that horse grows.

Liquidity of the market

The liquidity of the market has a big impact on the odds of horses. A liquid market means that there is a potential to back and lay large sums of money. Big race meetings like the Cheltenham Festival tend to have very liquid markets, and as a result odds tend to be slightly closer to the actual odds of the horse. Any obvious discrepancies in the odds would be picked up by the huge amount of punters, who will find the best value from a different bookmaker. Smaller races with less liquid markets often provide less accurate odds because they are scrutinized far less with less money riding on them.

Backers and layers

On betting exchanges, such as the Betfair Exchange, customers have the choice to back a horse (to win) or lay (bet against) the horse at odds that they choose. Bets must be matched for them to be worth anything- For a punter hoping to back Horse A @ odds of 4.0 (3/1) there must be another punter happy to lay the horse @ the same odds for his stake. The exchange markets have a huge impact on a horse's odds - where there are a larger number of people laying a horse, rather than backing it, the odds will lengthen and vice versa.

We hope that this introduction to factors that affect a horse's odds was beneficial to you and wish you the best of luck with your betting.