DOBBING is a word I came across around ten years ago in connection with in play/in running betting, writes Dave Renham. DOBBING is usually shortened to ‘DOB’ which means ‘double or bust’. Essentially it is an in play trading strategy. If the trade/DOB is successful, we double our original stake, if the trade/DOB is unsuccessful we ‘bust’ or lose our stake.

What is DOBBING?

For people who have not heard of DOBBING before I will give you a worked example which hopefully will help:

Let us imagine you back a horse at 10.0 for £10; in order to create a potential DOB you try and lay the horse at half the odds for double the stake – so you set a lay at 5.0 for £20. If the horse hits 5.0 or lower in running, your lay bet will be matched and regardless of the result you will win £10 (less commission).

Here are the basic mathematics behind the two potential winning outcomes:

- If the horse goes onto win the race, you get £90 returned from the ‘back’ part of the bet while you lose £80 on the ‘lay’ part of the bet. This gives you a £10 profit.

- If the horse does not go onto win but reaches 5.0 or lower in running, then you lose your £10 stake from the ‘back’ bet, but gain £20 from the lay part of wager – again giving a £10 profit.

- If the lay part of the bet is not matched with a horse that does not win the race, you lose your original £10 stake.

 

The table below is another way to look at it, showing the three possible outcomes:

 

For dobbing to be profitable long term, we are probably looking to have a success rate of around 54% or more. This figure has to be a bit higher than a 50.1% baseline as we need to take commission into account.

As Russell Clarke mentioned in the first of his excellent in running articles (which you can read here), only about 20% of all money traded on a horse race occurs in running. Hence, there are far fewer people that trade in running compared with those that don’t. I am sure there are plenty of you out there who have thought about betting in running, but have decided against as it is not for you. There will be some of you who trade and are very successful. Personally, I do dabble in running from time to time, but despite using the market leading trading software, I know I am up against seasoned trading pros. I might be able to produce pre-race plans that are as good as most, but my decision making / speed under pressure is definitely not at the expert level.

An advantage of using this dobbing idea for some punters/traders is that you can place both parts of the bet/trade before the race starts. Therefore there is no need for trading software and you do not have to make quick decisions in running because you have made them already. Hence if you are like me, this is potentially a big plus. However, as the saying goes ‘for every positive there is a negative’. I find I say this phrase regularly in my life away from racing.

I tutor maths and chess online, and my chess students regularly hear this positive/negative quote pertaining to certain moves they make. It is the same here: let us imagine you set your ‘DOB’ pre-race and leave it to run its course. What happens if say you back it at 10.0 and set the lay at 5.0, but by the time the race starts the horse has drifted 15.5? OK the horse might still hit 5.0 in running, but this is going to happen far less often than it would if the starting price was 10.0. Of course the horse could shorten before the off as well, but as a general rule more horses drift than shorten. I know this because I have written about this before, and I have double checked recent data too. As an example, if we look at opening show prices compared to SP in 2023 (UK flat racing), we get the following figures:

 

 

Some pretty strong evidence to back up the general rule I mentioned above.

Of course there are ways round this potential issue by placing your back bet as late as possible; literally as the last horse loads in the stalls. The later you place it, the closer the price will be to its eventual Betfair Starting Price. That will mean however, that you will have to calculate and place the lay part of the bet immediately afterwards, and if you have literally placed your bet at the last second, you will be setting your lay after the race has got underway. Having said that, you should be able to put the lay price and stake in the Betfair machine before the horses have reached the end of the first furlong. This manual approach, though, clearly requires you to be around at the start of every race.

An alternative to avoid either the price fluctuating or needing to be tied to your trading screen at the start of each race, is to use some trading software. It is not too complicated to automate the software to back a horse at Betfair SP and once the Betfair SP is established, a lay at half those odds will be automatically placed. The lay will be calculated immediately the Betfair SP has been established (a few seconds after the off) to create the potential ‘DOB’.

DOB Examples

It is time to look at some races to see what can happen to Betfair prices in running. How many horses tend to DOB in a race, how many do not? Initially let me look at four races run on the same day (August 29^th 2023). They are all 10 runner events – I chose those races simply to make the ‘dobbing calculation’ easy to understand.

Race 1 – 2.15 Ripon 1m2f handicap (4yo+)

The result is shown below with the Betfair SPs (BSP) and the lowest price matched in running (IP LOW). The penultimate column (BSP/IPL) is the result of dividing the BSP by the IP LOW. For a successful DOB the BSP needs to have at least halved in price; hence showing a figure of 2 or more. Successful DOBBERS are highlighted in green:

 

 

In this example, despite nine of the ten horses shortening in price, only two (Bollin Margaret and Cedar Rapids) DOBBED. There was one near miss (Tele Red 1.90). If you watch the race back, or even just look at the in running comments, you will probably understand why there were so few DOBBERS. The early leader, King Titan, led for less than two furlongs and hence was never going to shorten in price enough leading for less than a fifth of the race, especially when the lead was a narrow one.

Cedar Rapids took up the running after 2f leading for the next six furlongs and, considering his starting price of 83.06 and that he was still leading 2f from home, it is fairly easy to appreciate why he shortened to 22 and hence DOBBED. Bollin Margaret then took over the lead having just passed the 2f pole and led to the finish. Hence, as a winner at a BSP of 13.36, Bollin Margaret was always going to DOB.

In addition, once Bollin Margaret took over, the nearest challengers never really looked like getting to her. We could have found that out by watching the race replay or by looking at the in running comments. The comments for Bollin Margaret were ‘took keen hold, prominent, switched right over 2f out, ridden to lead over 1f out, kept on well final 110yds, always doing enough’. Hence with none of her closest pursuers really looking like winning this helps explains why they did not DOB.

Obviously each race is different and the number of horses that DOB will not be the same proportion of runners in each race (as we will see).

IMPORTANT NOTE: Before moving onto the second race, it should be noted that race winners do not always DOB, because the BSP has to be at least 2.02 for a horse to halve in decimal price (to 1.01, the lowest value on Betfair). Hence odds on winners cannot DOB.

Race 2 – 4.00 Ripon 6f handicap (3yo+)

Onto a sprint handicap a bit later on the same card:

 

This time, three of the ten runners DOBBED, one more than the first race. In this race three horses led at various points: the winner Twelfth Knight, as well as Abate and Russco. Twelfth Knight and Russco both DOBBED, while Abate was a very near miss with a BSP to IP LOW ratio of 1.98. Horses that lead at some point in the race are usually going to shorten in price, sometimes considerably so. That is the type of pattern I would generally expect to see, and the first two races have conformed to that pattern.

Race 3 – 4.15 Newbury 1m 4f handicap (3yo only)

Over to Newbury now for a handicap over 12 furlongs:

 

This time we see over half the field (six of the ten runners) DOBBING, despite only two horses leading during the race. The high number of DOBBERS is almost certainly due to the fact that the winner Graham, who had been clear 4f out, started to experience that lead steadily eroding. Hence, many in play traders observing the pack close on the leader would have thought / hoped / expected that one or more of those challengers would potentially win. This almost certainly explains why two horses traded so low; Medieval Gold (2^nd) traded at 1.5, and Gordon Grey (4^th) traded at 2.06.

Race 4 – 6.30 Musselburgh 5f handicap (3yo+)

Here are the facts and figures for this Musselburgh sprint:

 

An even split here with five horses DOBBING and five not. Three different horses led, of which two DOBBED (Sixcor, the winner, and the runner up, The Grey Lass). Two of the other three that DOBBED come as no real surprise if you watch the race back. Beneficiary made good headway mid race and as he was a big price, he would have caught the eye of enough traders to see his price contract sufficiently to DOB. Favourite Aconcagua Mountain travelled strongly and a furlong out looked the most likely winner. He faded in the final furlong but not before trading as low as 1.56.

What these four races tell us is that every race is going to be different from a DOBBING perspective. Just like every race is different if you are simply backing a horse or indeed laying one.

DOB Anomalies

Readers should note, that there are occasions when only the winner DOBS. An example was the two-mile Goodwood Cup this year run on 1^st August. In this race, Quickthorn was well clear of the field after four furlongs, and a mile later with just half a mile to go he was still 20 lengths clear. The opposition assumed that Tom Marquand, the jockey of Quickthorn, had gone out too quick but they were sadly mistaken, and no other horse really stood a chance. Knowing how the race panned out explains why it was no surprise that no horse was really that close to halving in price in running.

Here is the result with the accompanying in running data:

 

This scenario of a single DOBBER in a race will occur from time to time especially in very one-sided events. However, it is extremely unusual for every horse in a race to DOB. In previous research from 2018 I had a dim recollection that there was a race at Nottingham where all the runners DOBBED. After doing some digging I found the race in question. It was the 7.25 on 7^th August 2018. It was a 10f handicap with six runners. Here is the result:

 

 

Not only did all six DOB, but they all DOBBED fairly comfortably. One reason for this may be that four of the six led the race at some point, while the two who didn’t, were close to the lead making headway at different points.

DOB Success Rates

Going back to the four 10-runner races I shared earlier, of the 40 runners, 16 DOBBED. This equates to 40% of the runners. Previous flat racing DOBBING research I have done, over different time frames, showed the overall DOBBING percentage average out at around this 40% mark. Considering we need a success rate of roughly 14% higher than this, there is clearly a job on to make DOBBING profitable. So, how can we improve upon this base figure of 40%? Here are some thoughts / questions, which I will aim to expand upon in subsequent articles:

1. How does run style affect DOB success? I have already discussed the fact that horses that take the lead at some point in a race are likely to shorten in price. Horses that lead for the majority of the race, or are leading at the furlong pole while looking like a potential winner, are both occasions when the leader’s price is likely to shorten considerably. Obviously if the price drops enough then the horse will DOB. Front runners, especially in sprints, are horses that are likely to have real potential to DOB; and, of course, the longer they lead the more chance of this happening. Hold up horses are not screaming out DOBBERS, unless they get into a much more forward position at the business end of the race.
2. You often hear commentators say that a horse is ‘travelling well’. Horses that are ‘on the bridle’ tend to shorten in price as they are not under any pressure, or so it seems. This is a potentially time consuming idea to test, but I want to put it out there.
3. Does race distance make a difference? Longer races mean greater elapsed time, and logic dictates that there will be more price fluctuation as a result of this. Hence, the chance of DOBBING may increase.
4. Do courses make a difference? Certain courses, Bath for example, have difficult camera angles in the final couple of furlongs. I remember trying to trade in running in a Bath sprint around ten years ago; never again! It was so difficult to monitor all the horses from a front on angle. Other course considerations I guess that may have a positive bearing on DOBBING percentages, such as those with uphill finishes, or with long home straights.
5. What effect does the price of a horse have? One sensible argument would be that shorter priced runners may DOB more often than longer prices, simply because the market suggests they will be more competitive: they are more likely to be mounting a serious challenge at some point in the race. An alternative argument would be that horses starting a long odds do not have to go ‘low’ in running to DOB. An 80.0 BSP shot only needs to reach 40.0 to DOB. Whereas a 4.0 (3/1) shot needs to hit 2.0 (even money).

My questions and thoughts don’t stop there, but it is time to wind up this introduction to DOBBING. As you can see we have a fair bit of digging and number crunching to do – or at least I do! And, at this stage I have only really discussed flat racing; I have not even mentioned National Hunt racing as yet...

- DR