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Track bias has become a hot topic in racing over recent years and an understanding of the concept is essential for every punter.

Once upon a time there was actually debate in racing circles about whether bias actually existed or whether it was a myth… simply punters reading too much into results on the day that could be explained by race tempo or other factors.  Nowadays track bias is accepted as a real factor in racing and debate is more about whether it existed at a given meeting and to what extent.


When we use the term “track bias” we are referring to anything that creates an advantage or disadvantage to horses racing in a certain position and / or certain part of the track on a given day.

For example, at Flemington on 2017 Newmarket / Australian Cup Day, horses racing on the rail or one off were advantaged compared to those that tried to run on 3 or more horses off the fence in the straight.

Since re-opening the Eagle Farm track in June 2016, we have regularly seen horses racing well off the fence in the straight do much better than those that were closer to the inside.

The presence of track bias not only has an impact on how you might perceive winning chances and betting opportunities on that day, but also how you interpret individual horse performances out of the meeting.

What Causes Track Bias?

There are a number of factors than can cause or at least influence track bias


Wear from previous races or track gallops is a key factor. If the rail is moved or left in a position which exposes the ground from a recent race meeting, then that worn ground can become either a clear advantage or disadvantage.

If the turf has recovered well without damage from the last meeting, then it will generally be more compacted and firmer (faster) for horses to gallop on compared to the fresh ground.

If the ground still shows signs of being marked / damaged from the recent meeting, then it won’t hold together as well once horses start running over it again. The fresher ground away from the wear and tear will be faster to gallop on.

There can also be wear from track gallops or trials / jump outs at certain venues where they use the course proper. That’s typically well away from the inside fence, but again, it can make those sections of the track firmer to softer to gallop on at a future meeting.

It would be nice if all race meetings were held on fresh ground, but that’s not always possible so previous wear and tear certainly plays a role.


There are various types of irrigation systems used across our race tracks and some are better than others. The key issue with all irrigation systems though is that they can’t water a track with 100% uniformity. The quality of irrigation system itself as well as the presence of wind when watering can cause different amounts of water to hit different parts of the track. The result is that some parts of the track end up with more moisture than others, which makes them slower to gallop on.

Victorian race tracks ended up with a bias rate of greater than 40% when they adopted a policy which saw virtually every meeting start the day as a “dead 4” on the old scale. To achieve that they had to use much more irrigation than normal in the 24-48 hours prior to a meeting, which couldn’t possibly be done in a uniform manner. Thanks heavens they eventually scrapped that policy.

Natural rain is the only way that race tracks can be uniformly watered. Any time there is “irrigation” applied to the track there will be uneven watering and depending on the extent of irrigation applied, there is a risk of track bias.

Further issues can be caused at tracks where they use travelling irrigators, which are towed around a track with heavy tractors. Tractors naturally cause heavy compaction of the ground in that section of the track, making it faster to gallop on. Flemington is an example of this where the centre of the straight is often firmer due to the tractor driving over it many times.

It’s rarely a factor in races around the turns as it’s too far away from the fence for horses to get out to in the straight (without losing significant ground). However, it often comes into play in straight races where we see the field come down the middle of the track.

Country tracks don’t have anywhere near the same amount of money spent on their facilities as city tracks and often use irrigation systems that water far less evenly and have to be moved by heavy tractors.

Assessing the form when wet tracks are involved for either today’s race or in past runs can be a problematic process filled with a high degree of uncertainty. Some horses produce their best on dry ground, some need wet ground, while others are versatile and can perform effectively on all surfaces.

Click here for more on Wet Tracks


The impact of wind on track bias is two-fold. Firstly, it can impact how a track dries out leading into a meeting and secondly, if it is windy on the day then horses can be advantaged or disadvantaged depending on their position in the race.

For example, the presence of a strong head wind early in a race can mean that horses leading or racing without cover are disadvantaged by working into that wind. Those getting cover are advantaged as they are spending less energy to travel at the same speed.

A head wind in the home straight can make it more difficult for off pace runners as they need to work even harder into the wind at the business end of the race to make up ground. Even strong winds that hit runners from the side can be a disadvantage compared to those racing outside them that are protected from the wind.

Just as importantly, wind in the lead up to a meeting has a huge bearing on how the track dries out and the evenness of irrigation (mentioned above.) Depending on the direction of the wind certain parts of the track can be more exposed than others. Areas that are more exposed to wind will dry out faster and can be a full rating or two better compared to areas that are more protected from the wind.

If the home straight at a track is more exposed to wind leading into a meeting and dries out faster than other sections, it can become an advantage for horses near the lead as they will get onto that firmer ground sooner than those behind them.


The design of a track including its undulations, camber around the turns (i.e. the slope of ground from outside to inside) and general drainage system affects how it dries and therefore the areas that end up firmer than others. This is very much specific to each track and can be best observed by historical patterns.


Machinery that is used to maintain tracks can also play a role. Mowers used to cut the grass or spray units that get towed with tractors to apply fertiliser, insecticides etc, can result in some areas of the track becoming more compacted and firmer to gallop on, depending on where they are driven and how often. Track managers naturally do their best to combat this, but it’s not always possible.


Aeration involves creating openings in the turf to help air, water and nutrients move into the soil to the grass roots. It’s a necessity to keep turf healthy, but naturally softens the structure of the soil.

As long as the entire track is aerated evenly then it shouldn’t cause major bias. However, at some tracks (i.e. Flemington) they sometime use aeration to try and soften firmer parts of the track and make the entire surface more even. If it works, great, but it can go wrong and end up creating bias. The aeration practices at a track is something we rarely hear about, but it can certainly play a role.


The effect of bias on a race will largely depend on how significant the factors creating the bias are. Rest assured though that the presence of notable track bias will have a clear impact on the results of each race.

I will never forget the 6th November 2013 at Kyneton as the first two races on the day presented the clearest indication you will ever find about the impact of track bias.

In race 1 we saw the Darley trained Boer backed from approximately $1.35 into $1.30 in a maiden race after providing competitive in Saturday class races at his previous preparation. He raced just off the lead, took over in the straight and the result seemed a formality.

However, an $11 chance that was 6L off the lead at the 600m and shown the whip before the turn, peeled wide in the straight and ran on down the outside, sprouting wings over the final 200m to run down Boer.

I thought nothing of it at the time, Boer simply looked disappointing. Then came race two, where we saw a 3YO gelding by the name of Chautauqua backed from approximately $1.30 into $1.20. He led this Maiden race and again the result seemed a formality as he kicked 2L clear on straightening without being fully pressured. However storming home from the back came a $15 chance wider in the straight and he ran past Chautauqua to win the race.

The inside proved to be a clear disadvantage at Kyneton that day and while no one can say for absolute certain that was the difference between Boer and Chautauqua winning or losing, it’s more than reasonable to conclude it was the key factor. For the record, Boer raced on the lead again at his next start and won by 5 lengths, while Chautauqua led again at his next start and won by 4.5 lengths.

Of course, not all bias is that significant, but when you consider that most races are won by relatively small margins, any disadvantage in a race has the potential to create an entirely different result to what might happen in more neutral circumstances. Horses travelling in slightly softer ground for an entire race or even the last 400m to 600m of a race means they have to spend more energy to travel at the same speed as others. That disadvantage changes the outcome of races.


This question could be the subject of a long article by itself. Predicting bias before a meeting can be accurate in cases where historical patterns are well and truly established. For example, when the rail is out at Moonee Valley then horses closer to the fence are typically on the firmer ground, which makes it much more difficult than normal (but not impossible) for those horses trying to run on out wider. Well credentialed horses that settle in the first 4 in-running are excellent betting prospects (very profitable), while those settling further back return a significant loss and are a big risk!

In other cases, it can be far less reliable predicting bias due to the number of factors that influence it and a lack of certainty about just what has happened at the track in the lead up to a meeting. The best approach you can take is to look up past meetings that were held with a similar rail position, track condition, irrigation level and weather to the upcoming meeting. Was there a clear pattern on the day?

Be sure that your observations take account of some of the factors mentioned below about spotting track bias, otherwise you might make an incorrect assumption.

The level of irrigation prior to a meeting is an often-overlooked indicator. As discussed above, it’s virtually impossible to ensure even watering of a track from any irrigation system. If you read or hear that there has been significant irrigation in the 7 days leading up to a meeting and in particular the last 24-48 hours, then it can increase the chance of a bias occurring on the day.

If you are serious about factoring track bias into your work as a punter, then it’s far more efficient to set up a process where you record bias observations during a meeting or at least after the meeting if watching replays. It’s then easy to look up those details when doing your form for an upcoming meeting.

Even if you do that, it won’t be possible to predict every bias before the meeting, you will often need to wait until you see what happens on the day.


The key to determining if there is track bias at a particular meeting is to answer the question

Is there a pattern of horses with common characteristics doing things significantly better or worse than their market price suggests?


  • Where a horse settles in the field relative to both the leader and rail (i.e. on rail, 1 off, 2 off etc.)
  • Whether the horse has cover in the run or races without cover
  • Where a horse is positioned on the turn both relative to the leader and rail
  • Where a horse makes its finishing run in the straight (i.e. on rail, 2 off, 4 off, 6 off etc.)

I will typically look at horses that win / place and short priced runners that might perform well below expectations. It’s also important to be able to make an assessment of the early pace in each race as it provides important context that all of the above needs to be assessed in relation to.

Common characteristics about winners or placegetters does not mean there is a bias if those horses were expected to run well and / or the pace of the race has been very suitable. For example, if you see races 1 and 2 won by the leader, but they were both favourites and suited by a moderate pace then that’s no indicator of a bias at all. Those horses were expected to win or at least run well and had race pace to suit.

On the other hand, if both leaders were at longer odds and you also noticed short priced runners that failed to make up much ground by trying to run on down the middle of the track, then you could rightfully have some suspicions that there may be a bias. Pay careful attention to what happens in the next race.

It’s also important to not only focus on the home straight when trying to identify bias. Where horses settle in the run can also provide clues. For example, at the Canterbury night meeting on 17th February (heavy track) eight out of eight winners and seven out of eight runners up settled on the fence in the run.

That group of 15 horses included a number at double figure odds (including one at $81) that ran significantly better than their starting price suggested.

The reverse can also happen where horses that settle on the fence early and into the straight seem to struggle and the meeting is dominated by horses that settled two or three wide and peeled out to run on well off the fence.

Remember that a bias does not make it impossible for horses to win or run well against the pattern. It’s about relative advantage or disadvantage and you need to make your assessments based on the sum total of the information you gather.

At some meetings, the bias is so obvious that even a casual observer can notice it. At other meetings, it might be less obvious but nonetheless still a key factor. There are no fixed rules, it is very much a subjective concept and you have to decide how important it is.


The concept of bias is relevant to betting in two key ways

  1. On the day – if you predict a bias will exist or start to observe bias on the day, how you do factor that into your betting decisions?
  2. Post-race – if there was a bias that existed, how do you interpret the form out of a meeting and assess advantaged or disadvantaged horses at their next start?


Bias is still one of the factors which the market does not fully compensate for in its pricing, even as it develops on the day. That means you have the opportunity to improve your betting results by adjusting your decision making in those cases where you’re confident that a bias either will exist (if predicting before the meeting) or actually does exist after a couple of races.

Depending on the bias, I can offer you the following advice for betting:

1. If you expect or notice that runners closer to the inside and / or closer to the lead are likely to be advantaged:

  • Don’t back any horse you think will settle further back than 1st to 4th in the run, no matter how much you like them. History shows that when those closer to the fence / lead are advantaged, horses further back in the field lose a significant amount on turnover (>40% POT). Is the market really making a 50%+ mistake in the price of the horse you like? It takes discipline as you will miss the odd winner, but over time those bets will cost you a small fortune and you will be far better off avoiding them.
  • If you like an on-pace runner, then bet with confidence. Don’t be put off by a wide barrier, uncertainty about the distance, weight or any other secondary factor. The percentages are in your favour.
  • Scenarios where you like a horse that will settle handy to the lead and the main danger is likely to settle back are especially appealing.

2. If you expect or notice that the inside will be a disadvantage and horses off the fence will be best suited:

  • Consider passing on the entire meeting, depending on how significant the bias is. Horses that get wider can still be disadvantaged if not wide enough or in the fastest lanes (i.e. those that might have been compacted more by track equipment driving over them.) Furthermore, the pattern can change as the meeting progresses with winners coming progressively wider in the straight. This scenario makes confident betting very difficult.
  • If you decide to bet, then barriers should be viewed in the opposite way to the common perception. i.e. inside barriers are a disadvantage and wider barriers are an advantage, regardless of likely in-run position. Statistically speaking, barriers 1 to 4 when the inside section of a track is clearly a disadvantage have a 4 x worse POT% compared to barriers 10+
  • Horses that are drawn inside and are likely to settle midfield or worse in the run are the very worst type of betting prospects. On the other hand, they can be good lay betting prospects.
  • The best type of betting prospects in this scenario are mid to wide drawn horses that will settle midfield or just off and look to peel wide and run on in the straight.


Assessing the performance of horses out of a meeting that was influenced by bias can be difficult. Following are some general guidelines:

  • Be prepared to totally overlook the run of a horse that was disadvantaged by the bias. In these cases, the starting price (expected performance) of the horse should be more influential in your form assessment. You can gauge the extent of the disadvantage and performance by comparing to other horses that raced in a similar position either in that race or on the day in other races.
  • Be cautious about horses that produced a sudden improvement in performance when suited by the bias. This is especially true if they ran much better than their market price suggested and / or have already had 15+ career starts and were well into their preparation.
  • Take note of horses that seemed to run well against the bias on the day, even if they didn’t win or place. It can be that little bit of extra information you need to give you confidence about backing the horse at its next start.
  • Be harsh on horses that were suited by the track bias and still ran moderately or worse.


Track bias is an important factor in racing and while it may be easier to ignore, a little bit of understanding and thought can make a big difference to your betting results over the course of a year.

You don’t need to become obsessed about it or look to attribute every unexpected result to bias in the track. However, you should maintain a general awareness when watching races and pay attention to respected experts that might comment on it either before or during a meeting.

When it seems relevant, use that information with the above guidelines to help make your betting decisions. There are no fixed rules, it’s about weighing up all of the information and making decisions that feel right to you, regardless of the race outcome.

If you do that consistently, your results will definitely improve and every extra percentage point you gain is great for both your confidence as a punter and of course, bank balance.

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