Tag Archive for: PRB

Evaluating Jockeys by Percentage of Rivals Beaten

/in /by

In this article I will put 35 jockeys under the microscope, writes Dave Renham. These are the riders with the most rides per year, on average, over the past four years. The data has been taken from UK flat racing (turf and all-weather (AW) and the full years 2021 to 2024.

Introduction

I have further limited the findings to mounts sent off at an Industry Starting Price (ISP) of 20/1 or shorter, in order to try to eliminate most of the horses that had little or no chance; and, further, because very big-priced winners tend to skew profit figures.

For this piece I will primarily examine the data using ‘Percentage of Rivals Beaten’, although I also plan to look at strike rates and A/E indices. Percentage of Rivals Beaten (PRB) is a calculation based on a horse's finishing position in relation to field size. It makes key distinctions between a horse finishing, say, fourth in a seven-horse race (PRB 50%, three rivals beaten, beaten by three rivals) and finishing fourth in a sixteen-horse race (PRB 80%, twelve rivals beaten, beaten by three rivals). We express the PRB as a number between 0 and 1. So, in the examples above, 50% is 0.5 and 80% is 0.8.

As racing researchers we can often be blighted by small sample sizes when analysing, for example, win strike rates. Hence, there is a strong argument to suggest that PRB figures are a more accurate metric, simply because they make datasets bigger: they award a sliding performance score to every runner in every race, whereas win strike rate only awards the winner a score with all other finishers getting zero.

Today's offering has a slightly different flow from usual I will be writing it "as I go along". In other words, I’m sharing the research and my thinking process stage by stage, rather than doing all the research and then writing about my findings afterwards. Thus, my main commentary will appear to be in the present tense. If that makes sense, let's crack on (and if it doesn't, it soon will!)

Top Jockeys' PRB: Overall

I will start by sharing the average PRB figures for each of the 35 jockeys over this four-year period. They are ordered alphabetically across two graphs:

 

 

 

 

To provide a benchmark, the average figure when combining these jockeys was halfway between 0.58 and 0.59, so 0.585 to be precise. Oisin Murphy has the highest PRB figure, 0.64, followed by five jockeys tied on 0.62 – William Buick, James Doyle, Rob Havlin, Jack Mitchell and Danny Tudhope. Tom Eaves, Cam Hardie and Andrew Mullen have the joint lowest PRB figure of 0.54.

It should be noted that all riders in this sample are above the 0.5 PRB benchmark and so even the lowest in the cohort are out-performing the norm.

Top Jockeys' PRB: ISP 6/4 or shorter

Although I have restricted qualifiers to those priced 20/1 or shorter, there are clearly some jockeys who have more rides at shorter prices than others. Hence, I am assuming that jockeys should have higher PRBs because of this. To help analyse and potentially confirm this hypothesis I am going to look at the percentage of rides each jockey had with horses priced 6/4 or shorter. The table shows the splits:

 

 

There is a huge variance here, from William Buick with more than 13% of his rides sent off 6/4 or shorter, to Cam Hardie at less than 1%. Of the six jockeys with the highest average PRBs I noted earlier, five of them were in the top six for the highest percentage of rides (highlighted in blue in this table). Therefore, we can see there is a strong looking correlation between price and PRB, as we should expect.

Top Jockeys' PRB: ISP 12/1 to 20/1

It makes sense next to look at the percentage of rides each jockey had when the qualifiers were bigger prices in order to consider both ends of the price spectrum. Therefore, below is a table showing these percentages when considering percentage of rides from runners priced 12/1 to 20/1.

 

 

The three jockeys with the highest percentages (shown in blue) are the jockeys who had the lowest overall PRB figures shared earlier, namely Tom Eaves, Cam Hardie and Andrew Mullen: this is further evidence of clear positive correlation. Also, the lowest four percentages in this group are for Messrs Buick, Murphy, Doyle (James) and Mitchell.

At this early point in my research I am starting to appreciate that despite the fact that PRB is a really useful metric, for this type of research the price of runners is also very important and can significantly sway the balance one way or the other. Hence, the market will be factored in for the remainder of what follows.

Top Jockeys' PRB by Price Range

Having established the importance of the starting price, I have decided to calculate PRBs for different price bands for all 35 jockeys. The brackets I am going to use are again based on Industry Starting Price and they are as follows:

 

 

In the table below I have collated the PRBs for each jockey for each price band. The average figures for all jockeys in the list are shown in blue at the bottom of each column, and I have highlighted any PRB that is at least 3% above the average or at least 3% below the average. The 3% ‘above group’ (positive) is highlighted in green, the 3% ‘below group’ (negative) is in red.

 

 

The colour coding helps to highlight jockeys that seem to perform above the norm and those that may have performed below what might be expected within each price band. There were three jockeys who obtained two ‘greens’: Robert Havlin, Clifford Lee and Kieran O’Neill. And there were four jockeys who obtained two or more ‘reds’: William Buick (3), Holly Doyle (2), Joe Fanning (3) and Rob Hornby (2).

 

Top Jockeys' PRB: All-Round Performance

I am thinking that another way we could analyse these data is to simply add up each jockey’s six PRB figures in the above table and compare them.  Below, then, are the riders with the top ten combined PRB figures when adding the six values together:

 

 

It could be argued that these are the top 10 performing jockeys from my original list of 35 as their totals are based on the overall performance across different price ranges. From looking at these findings I would be happy to see one of these ten riding a horse I am keen to back. Rab Havlin, who has consistently shown positive figures in the research to date, tops the list on a combined total of 3.99. (0.88 + 0.76 + 0.68 + 0.65 + 0.55 + 0.47).

Next, here are the lowest ten combined PRB totals from our sample of the top 35 riders:

 

 

As can be seen, we are talking small margins here so despite these ten being at the bottom we know that they are all still top-notch riders. However, in terms of PRB figures within certain price bands, they have performed with slightly less success than the rest of the jockeys in this sample.

To complete the set here are the remaining jockeys (positioned 11th to 25th) with their PRB totals. Due to the bigger group, I am using a table rather than a graph:

 

 

Top Jockeys: Other Metrics

I stated earlier that PRBs are arguably the most accurate metric but it always prudent to consider other metrics where possible in order to attain a stronger 'feel' for the data.

We know that finishing fifth in an 18-runner race will produce a better PRB figure than finishing eighth in the same the race, but usually finishing fifth does not make punters money (unless those generous bookie types are offering extra places).

At this point, then, I am thinking about the key battles in terms of finishing first rather than second and, therefore, I am going to share the wins, runs, strike rate, profit/loss and A/E indices for all 35 jockeys. As with the PRB data this does not include rides on horses priced over 20/1 ISP. Profits and losses have been calculated to Betfair SP less 2% commission. The A/E indices are based on Betfair prices and any figure above 1.00 has been coloured in green:

 

 

Somewhat surprisingly, 18 of the 35 jockeys have secured a profit which is impressive considering there are not any really big BSP winners to skew the returns. In fact, the highest winning BSP was 46.0 and there were only three winners in total above BSP 40.0, and only 23 above BSP 30.0 (out of total of nearly 12,000 winners).

Rossa Ryan, Saffie Osborne and William Buick have the best ROI%s (above 7%), and they each have one of the top five A/E indices. Impressively, Ryan has made a blind profit in each of the four years, Osborne and Buick matching that feat in three of the four years surveyed. There are two jockeys that made a loss in each of the four years, namely David Allan and James Doyle.

Conclusions

All this is helping me, and hopefully you, to start building a more complete picture of jockey performance; or, at least, the performance of these 35 top riders. The PRB data have given us an extra layer on top of the usual metrics we focus on. However, it is becoming clear to me that for this type of jockey-based research we do need other metrics (win percentage, profits, A/E indices, etc) to bring betting utility to the party.

I am just starting to expand the jockey PRB research into other areas and there is plenty more to share; so I have come to the realisation that this article will spawn a second piece. Thus, it is probably too early to draw any key conclusions from the research so far as there are more pieces of the puzzle to add.

However, next week I have a Royal Ascot article ready to go, so it affords me a little extra time to do further digging for part two of this jockey deep dive!

- DR

Gold Upgrades: May 2023

/in , /by

It's been a while since we've released any new features to Gold, so I'm excited to share a couple of small - but awesome - upgrades with you. The first may be imperceptible (but probably won't be), the second is niche, and the third is a new rating... let's get to it.

1 Remember settings

You know how you always do the same thing when you go to the cards to see the info that's right for you? For me, this means setting the draw tab to 'Actual' and PRB/PRB3/PRB in the three dropdowns; and setting the Pace tab heat map to 'Place%'; and incessantly re-sorting the Instant Expert grid when I change one of the top of the page variables.

Well, no more... yay!

Why?

Because we've introduced some 'local memory' improvements so that things remain as you set them up if you're using the same machine as the one you set them up on. Here's what I mean: let's say you, like me, look at PRB views on the 'Draw' tab.

 

Up until now, if you were logged out or otherwise left the site, you'd have to re-select the parameters as you like them. But, from now, you'll see those settings remembered and appearing as a matter of course when you go to the tab.

Likewise, that minor irritation of having to re-sort the Instant Expert table after every variable amend:

 

Not any more. Now you can change anything at the top of the Instant Expert and the grid will remain in the order you had it. Phew, what a relief!

 

We've added 'remember' functions to all tabs, which will certainly save me a goodly few clicks most days, and hopefully ease your transit around the cards a little, too.

N.B. This is the case if you're using the same machine/browser and don't clear your cache/cookies. Even if you do clear cache from time to time, like me, it's still only an occasional faff to redefine your parameters. And that will remind you of when you had to do it every time and make you grateful 😉

 

2 Added PRB to Pace 'Heat Map' view and table

I've wanted this for a loooong time. Trying to infer the impact of the combination of draw and run style can be really difficult when the sample sizes are small, which is why I use 'Place %' rather than 'Win %' - because place percent gives meaning to each of the placed horses, whereas win percent only does that for the first one home.

Let's say we only have four ten-horse races in the sample size. That would mean 12 placed horses and just four winning horses. Obviously, then, the heat map could be skewed especially when looking at win percent.

PRB - Percentage of Rivals Beaten - assigns value to every runner in every race, aside from the last horse home whose value is 0 (0% of rivals beaten). In our fictional four race sample above, we now have 40 (or 36 if you exclude Tail End Charlie's) scored horses from which to form some sort of perspective.

Anyway, PRB is better in my view, especially when looking at almost any flat turf race (the all-weather sample sizes tend to be much larger and, therefore, more meaningful in traditional win/place strike rate terms).

 

Note the PRB option in the dropdown box top right and, directly below that, a new PRB column in the pace table. This will immediately be my 'de facto' setting; and, of course, in this brave new world that setting will be remembered!

3 Introducing Performance Ratings

Everyone loves a rating, right? Here at geegeez we have a fair number these days, what with official ratings, Racing Post Ratings, Topspeed, Peter May's private ratings, and our sectional upgrade figures - and that's assuming you don't use our ratings tool to create and save your own 'R1' numbers! But these Performance Ratings are pretty nifty and I think they'll add value for some users at least. What are they? I'm glad you asked...

These are the BHA's own race figures. They differ from Official Rating (OR) in that they are a measure of the level to which a horse has been judged to have run in a specific race. So, for a horse going up the handicap, OR and the Performance Rating (PR) will be the same.

Here's Sayifyouwill, a last time out winner off 79 - she was raised 3lb to 82 for that, as a result of her PR for the last day win being adjudged to have been 82:

 

 

But when a horse runs below its handicap mark, it won't necessarily be dropped to its performance level. For instance, Cry Havoc won a couple of times before running poorly on her most recent two starts:

 

 

Looking from bottom to top, we see she was 1st of 14 and, running off 79, was raised to 82. She then won in a field of 11 off her revised OR of 82 and was awarded a new PR of 86. On her penultimate start, when sixth of eight, she ran to a PR of just 69 and yet her handicap mark (OR) remained unchanged on 86. Another poor run, this time eliciting a PR of just 34 when running off 86 and trailing home last of six followed. After that, she was dropped a pound to an OR of 85 (not shown).

So what do these PR figures tell us? Well, they quantify the degree to which a horse may have underperformed and, when looking at the last few runs of a horse, they can help us build a profile of progression / regression in a similar way to RPR.

PR figures will start building as a history from now - we don't have the historic data, unfortunately - and there are some caveats, as follows:

- We will never publish a PR figure where there is no published OR (in other words, before a horse receives a handicap mark)

- We will never publish a PR figure for runs prior to the awarding of a handicap mark

- We will never publish a PR figure for Irish racing

The reason in each case is the same: we don't have access to them! Such data are a closely guarded secret at BHA towers and we are permitted to publish only what is available on the BHA website itself.

NOTE: You need to 'turn on' the PR ratings from the Racecard Options area of your My Geegeez page:

 

Over time, I feel that these PR figures will be a useful guide to horses' form profile and may also help to shed some light on optimal conditions for more exposed runners.

For more information on Performance Ratings, check out this article on the BHA's website.

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That's all for now - I hope there's something of use to you in the above.

Good luck,

Matt

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