Tag Archive for: steamers

Steamers and Drifters: Part 2

/in /by

In this follow-up article I am once again looking at market movement between the bookmaker’s opening show and the returned Starting Price, writes Dave Renham. The data I've used has been taken from 2018 to 2022 for all UK flat and all-weather racing. Bookmaker data is taken from William Hill.

In the first piece, which you can read here, the overall stats showed that a bigger percentage of horses drift (lengthen) in price from their opening price than shorten, when comparing market movement from opening show to SP. The biggest difference can be seen in horses that open 10/1 or bigger; of these over 42% drift in price compared with 29% that shorten.

Up to now in this research, I have not considered how much the price changed. Clearly all price movement is not the same; for example, a horse can drift from 4/1 to 9/2, but another 4/1 shot could drift far more dramatically out to 10/1 as an extreme, but perfectly credible, example. Likewise, horses that shorten in price can vary markedly in terms of how much their price contracts.

At this point I want to discuss what I mean by "significant price changes" as we need to be clear that looking at the difference in two prices does not necessarily tell the whole story. To help explain what I mean, let me give you some context. Let us consider two horses:

Horse A – whose opening price is 40/1 and whose SP is 20/1

Horse B – whose opening price is 6/4 and whose SP is Evens

If we focus solely on the prices, Horse A has shortened more because 40/1 to 20/1 is a 20-point truncation, whereas for Horse B moving from 6/4 to Evens is only a 0.5-point move. However, in terms of the chance of winning, Horse B has actually improved its chances more. In order to appreciate this, we need to understand the percentages behind the odds – in other words the percentage chance of winning according to the odds. The table below illustrates this:

 

 

As the table shows, Horse A has improved its chances of winning by 2.4% (4.8% minus 2.4%). However, Horse B has improved its chance of winning by 10% (50% minus 40%). Knowing and understanding betting odds in terms of the percentage chance of winning is very important. When I wrote my article on trying to create an odds line, the percentage chance for each horse was something I touched upon. Without it, you cannot easily create an accurate odds line.

At the end of this article, I have produced a table with fractional odds, decimal odds and the implied probability (percentage chance of winning) for betting prices. Readers, if required, may use it as a ready reckoner to convert odds into percentages.

It is now time to compare horses that shorten considerably from opening show to SP with those that lengthen/drift considerably. I am going to only consider horses whose prices have changed, in win percentage terms, by 10% or more. Hence the 6/4 to Even money horses mentioned earlier will count, but not the 40/1 into 20/1 ones. (N.B. The word ‘steamer’ is often used about a horse whose price starts to drop dramatically so for the rest of the article I will use ‘steamer’ for horses that shorten in price).

Let's look at strike rates first – for horses whose win chance changes by 10% or more due to their odds move:

 

 

These figures correlate with the findings of the first article and the general data set. Steamers have won 5.5% more often than drifters. However, this does not mean that steamers have produced better returns. In fact, it is quite the contrary as the graph below shows:

 

 

These strong steamers actually lost over 13 pence in the £ betting to Betfair SP; drifters lost just 1p in the £. The full breakdown of the results is as follows:

 

 

A 10%+ change in win percentage between opening odds and SP only occurs roughly once a day on average. Hence, this type of percentage movement can be considered a major price change.

I thought it might be interesting to breakdown the results further by splitting them by the odds at which they opened. Here are the stats for the steamers:

 

 

I have tried to group them so that the number of runs for each group is similar. What seems to be clear is that the worst performing steamers from a profit/returns perspective were those that opened at 11/2 or bigger. The shorter prices of 6/4 or shorter also fared relatively poorly.

Onto drifters now. There are not many big prices here because a 10%-win probability movement is impossible for horses priced 9/1 or bigger. For an extreme example to illustrate this, a horse drifting from 9/1 (10% chance) to 1000/1 (0.1% chance) has a win probability price movement of only 9.9%:

 

 

The results for drifters are more consistent in terms of profits/returns – there is very little difference between the worst performing price band and the best one.

It is clear from this data that if betting at BSP, significant drifters are better value than significant steamers.

 

Trainers

It is not worth looking at individual trainer data for the strength of steamer/drifter (+ / - 10%), as the sample sizes are going to be too small. Therefore, I am going to focus on trainer data for those horses whose prices changed in win probability terms by 5% or more, rather than 10%. This would include, for example, a horse shortening from 8/1 to 5/1, or one drifting from 6/1 to 10/1. I also restricted the runners a little by looking at horses that opened in price between Evens and 50/1. I ignored odds-on runners and those priced 66/1 or bigger for two reasons: firstly, because the majority of punters do not bet in these price brackets and, secondly, the individual trainer sample sizes are extremely small.

Steamers - As noted above I have broken down trainer performance where the win probability implied from opening odds to SP has improved by 5% or more. Trainers with at least 100 qualifying runners are listed. They are ordered by strike rate/win percentage:

 

 

The strike rates are decent as you might expect for steamers, but only a handful of trainers have made a profit. The Johnston and Channon stables have both done well from a profit perspective, as has Mick Appleby. Of course, for steamers, any value is gradually diminishing as the price is contracting.

Ten trainers have produced losses of more than 20 pence in the £, which is quite significant especially considering we are using BSP. The Crisford stable has the worst returns, edging above 30% for their losses.

Of course, if you could predict the steamer before it started shortening in price, and bet before it moves markedly, then the likelihood is that most of the trainers in the list would become profitable. Unfortunately, none of us has a crystal ball, which makes those types of predictions somewhat tricky! What would be interesting to find out is what percentage of horses that initially shorten from opening show, continue to shorten. Likewise, it would be really useful to know what percentage of horses that initially drift from opening show continue to drift. However, I do not have that information and guess the only way to find out would be by doing a live day by day data gathering exercise. That’s for another lifetime!

 

Drifters – Switching to drifters now below is a table of trainer performance where the win probability change from opening odds to SP has decreased by 5% or more. Trainers with at least 100 qualifying runners are once again listed.

 

 

There are six trainers in profit here with Stoute, Haggas and Balding drifters performing particularly well from a returns  and strike rate perspective. Indeed, all trainers in the above table have combined to secure a small profit of £21.52.

The two trainer tables I have shared indicate that at this 5%+ level of steam/drift, bettors might be better off backing drifters rather than steamers. In fact, if we look ALL trainers as a whole for both groups, we get the following overall figures:

 

 

Steamers, as we have come to expect, have the better strike rate, but drifters are offering punters much better value. So, the question is, do you want more chance of winners, or more chance of a profit?

Going back to the stats for Sir Michael Stoute in the second table above, his non-handicap drifters have totally outperformed his handicap drifters as the chart below shows:

 

 

Strike rates are similar but there is a big difference in the profits. Non-handicap drifters of this strength (5%+) would have secured Stoute followers impressive returns of 70 pence in the £ to BSP.

I must admit this has been a very interesting area to research. It is something I have looked at before but not in as much detail. It may be worthwhile comparing early morning odds to SP odds in a future piece, and also at some point I should see if the patterns I have found in these two articles correlate with National Hunt data. Anyway, as ever, I hope you have found the research enlightening, and all comments are appreciated as it helps me with my future work.

- DR

 

p.s. here is the table I mentioned earlier with fractional odds, decimal odds and the implied probability (percentage chance of winning) for betting prices.

Fractional Odds Decimal Odds Implied probability (% chance)
1/100 1.01 99%
1/5 1.2 83.3%
2/9 1.22 81.8%
1/4 1.25 80%
2/7 1.29 77.8%
3/10 1.3 76.9%
1/3 1.33 75%
4/11 1.36 73.3%
2/5 1.4 71.4%
4/9 1.44 69.2%
1/2 1.5 66.7%
8/15 1.53 65.2%
4/7 1.57 63.6%
8/13 1.62 61.9%
4/6 1.67 60%
8/11 1.73 57.9%
4/5 1.8 55.6%
5/6 1.83 54.5%
10/11 1.91 52.4%
Evens 2 50%
21/20 2.05 48.8%
11/10 2.1 47.6%
23/20 2.15 46.5%
6/5 2.2 45.5%
5/4 2.25 44.4%
11/8 2.38 42.1%
7/5 2.4 41.7%
6/4 2.5 40%
8/5 2.6 38.5%
13/8 2.62 38.1%
7/4 2.75 36.4%
9/5 2.8 35.7%
15/8 2.88 34.8%
2/1 3 33.3%
11/5 3.2 31.2%
9/4 3.25 30.8%
12/5 3.4 29.4%
5/2 3.5 28.6%
13/5 3.6 27.8%
11/4 3.75 26.7%
3/1 4 25%
16/5 4.2 23.8%
10/3 4.33 23.1%
7/2 4.5 22.2%
4/1 5 20%
9/2 5.5 18.2%
5/1 6 16.7%
11/2 6.5 15.4%
6/1 7 14.3%
13/2 7.5 13.3%
7/1 8 12.5%
15/2 8.5 11.8%
8/1 9 11.1%
9/1 10 10%
10/1 11 9.1%
11/1 12 8.3%
12/1 13 7.7%
13/1 14 7.1%
14/1 15 6.7%
15/1 16 6.2%
16/1 17 5.9%
18/1 19 5.3%
20/1 21 4.8%
25/1 26 3.8%
33/1 34 2.9%
50/1 51 2%
66/1 67 1.5%
100/1 101 1%
1000/1 1001 0.1%

 

The TRUTH About Steamers and Drifters

/in /by

In this article I am going to look at market movement between the bookmaker’s opening show and the final Starting Price and unearth some truth about steamers and drifters, writes Dave Renham.

In what follows I will be focusing on flat and all-weather racing in the UK spanning five years from 2018 to 2022. Bookmaker data is taken from William Hill.

Typically, the opening show tends to be around ten minutes before the off, and these are the initial prices the bookmakers set. Backing a horse at ‘opening show’ and seeing it shorten in price means you have probably gained a decent edge and potentially some value. Conversely, if you take the opening show price and the horse drifts (lengthens) in price, then you may have lost some value.

However, it is important to note that more horses will lengthen in price than shorten. Here is a graphic to illustrate this by looking at the percentage of all runners that either shorten in price, stay the same, or lengthen in price:

 

 

As can be seen nearly 42% of all horses drift, compared with 34% who shorten. Roughly a quarter of all runners see their price remain steady. It is interesting to note that the percentages are very similar when comparing handicaps with non-handicaps (within 1%), hence the market behaves in a very similar way from opening show until the off regardless of race type.

My starting point for researching this article is very simple – look at opening show versus Starting Price and seeing what effect the differential has on strike rate and profit/loss. In terms of profit/loss I am going to calculate returns to Betfair Starting Price. For the sake of simplicity, I am going to split the runners into three groups:

 

- horses that shorten in price from opening show

- horses that stay the same price as opening show

- horses that lengthen in price from opening show.

 

Using numerical examples:

 

 

Let me start by looking at all races.

 

 

As we can see, horses that shorten in price have comfortably the best strike rate, therefore, unsurprisingly, the market does tend to get it right most of the time. In terms of returns to Betfair Starting Price horses that have remained the same price have proved the best value by a couple of pence in the £. It may be interesting to note that there is little in it between horses which shortened in price compared with those which lengthened.

So, we have a very even looking starting point in terms of returns / value, now it is time to dig deeper.

Horses whose opening show price was 4/1 or shorter

I thought it made sense to look at different price brackets so let’s start with the better fancied runners. It also seemed logical to use the opening show price for this rather than SP as the opening show price is known pre-race. Here are the splits:

 

 

There is the same sliding scale in terms of strike rate, but it is the horses that lengthened / drifted in price that have been better value this time. Horses that shortened in price proved the worst value.

 

Horses whose opening show price was 4/1 or shorter and then lengthened in price

Focusing on this subset of drifters, it is interesting when you compare the results on Grade 1 tracks compared with other tracks. The Grade 1 tracks on the flat are Ascot, Doncaster, Epsom, Goodwood, Newbury, Newmarket, Sandown and York. Firstly, let’s review the win and each-way (win + placed) strike rates:

 

 

There is a difference of 1.6% in the win strike rates; 4.3% in terms of combining win and placed percentages (each way). These differences may look quite modest, but they are significant.

The graph below shows the return on investment (ROI%) to BSP for each group to highlight the significance:

 

 

Now we can see the significance of a 1.6% difference in win strike rates – the returns are over 7p in the £ worse at Grade 1 tracks for these shorter priced runners compared with the non-Grade 1 tracks. Indeed, away from the top tracks we see a situation where one would have virtually broken even backing every single drifter to BSP when it opened at 4/1 or shorter.

Whatever is occurring to create these differences between Grade 1 tracks and non-Grade 1 tracks for drifters, I am not sure. It may be connected with average field size; it may be connected with the quality of racing. It could be a combination of those, or neither.

Sometimes it is not worth speculating, especially as in this case it is nigh on impossible to isolate why. I’m happy on this one that it makes sense to just go with the data.

Before moving on I have checked the 2023 data (up to 27th Sept) and the same pattern for horses that drift/lengthen in price having opened 4/1 or shorter has continued:

 

 

The message according to all the information at my disposal is clear: horses which open at 4/1 or shorter and drift look to be POOR value when racing at Grade 1 tracks; away from these top tracks, such horses seem much better value – taking 2023 into account, going back to 2018 these runners would have lost you just 5p for every £100 bet.

 

Horses whose opening show price was 2/1 or shorter

Going back to data from ALL courses, if we focus on a shorter opening odds criterion of 2/1 or lower, and only look at drifters, we almost get to a break-even scenario. There were 7696 qualifiers of which 2801 won (SR 36.4%). Backing all 7696 runners at £1 stakes to BSP would have lost a meagre £49.13 (ROI -0.6%).

 

Horses whose opening show price was 2/1 or shorter that lengthened in price

If we once again look at the Grade 1 track data compared with other tracks for this subset of drifters, we see the following:

 

 

A similar, if stronger, pattern than with the 4/1 or shorter opening show cohort of drifters. Here, we are looking at a nearly 3% difference in win strike rate which equates to a difference of over 11p in the £ in terms of BSP returns.

As per the table above, drifters at non-Grade 1 tracks opening 2/1 or shorter have edged into profit. For this to happen across such a large sample – over 6500 runners – is interesting and impressive.

 

Horses whose opening show price was between 9/2 and 9/1

Time to look at the data for a bigger odds bracket. Here are the splits for each subset of the cohort whose opening show price was between 9/2 and 9/1:

 

 

It should have been no surprise to see those shortening in price winning more in percentage terms once again. In terms of returns, as with the shorter priced runners, horses that have shortened have been the worst value, albeit by just over 1p in the £.

 

Horses whose opening show price was between 9/2 and 9/1 that lengthened in price

I wanted to continue the comparison between drifters in this price bracket at Grade 1 and non-Grade 1 tracks to see if we get a similar differential as before. I assumed we would, as my expectations were that it would only start to reverse with longer-priced runners:

 

 

As before the non-Grade 1 track data is notably better, both in strike rate terms and BSP returns. However, the gap is starting to narrow, though the difference between the two is still clear. This dynamic has to switch around for bigger-priced runners and we will see whether this is the case shortly.

 

Horses whose opening show price was 10/1 or bigger

Onto double figure priced runners on the opening show now. Here are the results:

 

 

Horses that remained the same price have provided the best returns, while those shortening have marginally out-performed drifters. All groups though show poorer returns than the shorter priced runners we reviewed earlier. Both the shorteners and the drifters offered poor value for the punter.

 

Horses whose opening show price was 10/1 or bigger that lengthened in price

Finally for this section, I wanted to investigate whether this subset of drifters produced converse results whereby horses that raced at Grade 1 tracks performed better than those which did not.

 

 

Here, necessarily, we have the big switch around: horses racing at Grade 1 tracks have the better strike rate for the first time and their returns are much better than their non-Grade 1 track counterparts.

When comparing the results of horses running at a different level of racetrack, splitting up the drifters’ data into opening show price bands has been an eye opener for me. In the future, if my plan is to place my bet late at a Grade 1 track and my horse opens up 9/1 or shorter, I would think twice about backing it if it started to drift. Conversely if I was planning the same at a non-Grade 1 track then I would want to see it drift!

As it stands, the research shared so far has been very general – hence the huge sample sizes. I have not yet considered how much the price has changed, because clearly a horse can drift from 6/1 to 13/2, but another 6/1 shot could drift dramatically out to 10/1 and beyond. In a follow-up article I will be digging deeper into the size of the change in price.

Back to this article and, having looked at the splits in terms of strike rate and returns for different price bands, I thought it would be interesting to go back to where this all started and look at the percentage of all runners that either shorten in price, stay the same or lengthen/drift within each of these bands. Here are my findings:

 

 

This is very enlightening as we can see that the percentage of horses that drifted compared to horses that shortened is similar in the 4/1 or less group, and also in the 9/2 to 9/1 group (green/yellow bars). However, in the 10/1+ group, 42% of all runners drifted, compared to a much lower 28.9% of runners who shortened. These stats are implying that we should delay wagering longer-priced runners by either waiting to the last minute or simply using Betfair SP. For horses that open at prices of 9/1 or shorter, the timing of bet placement seems generally less crucial.

 

Trainers

Changing tack, a quick look at some raw trainer data now. I have chosen 25 high volume flat trainers, and I am simply comparing win strike rates and A/E indices for all of their runners within the three cohorts we’ve used throughout this piece – horses that shortened, horses that stayed the same price and horses that drifted. I have highlighted A/E indices of 0.95 or higher (in green) – these are essentially positive. A/E indices of 0.79 or lower (in red) are essentially negative:

 

 

There are more greens than reds and, as a rule, the strike rates increase as you read across the columns left to right. This is what we would expect based on the overall data presented earlier. However, George Boughey is interesting as his three strike rates sit very close together, between 17.25 and 17.72%. Horses of his that have drifted have proved much better value than those that have shortened.

Clive Cox has a poor record with horses that drift in price as does James Tate, perhaps suggesting these yards know when to bet! Meanwhile, David Menuisier has done extremely well with horses that have shortened in price. They would have provided you with returns of over 17p in the £ to BSP which is impressive: another yard to follow when they’re fancied maybe?

I wanted to delve a little more deeply into trainer statistics and analyse the percentage of runners for individual trainers that either shorten, stay the same price or lengthen.

Below is a list of trainers whose runners drift far more than they. I have ordered them by highest percentage of runners that lengthen in price:

 

 

It was surprising to see George Boughey in the list and even more surprising to see him at the top. I also had not expected to see Sir Mark Prescott or Gary Moore appear either. It may be that these horses are often put in at defensively short prices on the opening show, bookmakers fearful of shrewd trainers/connections landing a gamble. Elsewhere, some less well-known trainers are arguably more predictable entries in the table.

There are not many trainers where this scenario is reversed with the percentage of horses that shorten in price being higher than the percentage that drift. However, five well known handlers have this profile and are shown below:

 

 

There are some big guns in this list. Punters are aware of the skills of these trainers and hence their runners are usually going to be strong in the betting market. It may be that these yards are, generally speaking, less inclined to gamble their horses, though in the case of Aidan O’Brien that’s not typically the case.

*

It is time to wind up this first article into market movement. There are plenty of stats to chew over and hopefully for punters who bet near or around ‘the off’ it has given some useful data to potentially improve your profit/loss bottom line. You can read part two of this article here.

- DR