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MCLARKE

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Posts posted by MCLARKE

    SPEED RATINGS

    in At The Races - Racing Forum

    Posted

    I am fortunate in that my financial background meant I had to use computers for much of my work. I remember back in 1981 when I was a trainee accountant at British Steel there was a shiny new PC in the corner of the room that everybody was scared of but I took the plunge and started to use it. In those days it was a twin floppy disk set up with the system disk in one side and the work disk in the other (512kb capacity, I used to hate the disk full message). Lotus123 was the spreadsheet of choice, I used to love that (especially writing macros) and it took me till the mid 2000s to ween myself off it and move to Excel.

    Before I retired a few years ago I just used to bet on Saturdays, typing data from the Racing Post into my spreadsheets (I was too tight to subscribe to a data service).

    Since being retired I have had more time (too much according to my wife) to analyse and test data and I am reasonably happy with the returns from my AW systems.

    I would hope to have all my inital work done in the next couple of weeks before the flat season starts to kick in properly. Where it leads me we will see.

    SPEED RATINGS

    in At The Races - Racing Forum

    Posted

    1 hour ago, Trotter said:

    I'm still toying with the idea of rating the top race days ......... maybe days with Group Races on the card but I'll see how th

    It would be good if you could do that, we could then compare our results

    SPEED RATINGS

    in At The Races - Racing Forum

    Posted

    Right, I'm diving straight into the deep end !

    Be gentle with me, I'm an absolute beginner at this.

    I was going to concentrate on the all weather but as @Trotter says, we are now probably past the peak season for the AW.

    After rereading some of Nick Mordin's work he does state that the racing post standard times are valuable but compiling your own average times would produce more accurate figures. So, in for a penny, in for a pound.

    I will start with Ascot (purely based on the alphabet).

    I have taken data for 2022 (I am going to use 2023 as test data). For each race I have listed the date, class, distance and winning time. Most of this data I have been able to download automatically.

     1. Convert the data into seconds per mile. This shows the the fastest time was in a 5 furlongs sprint and the slowest time in the Queen Alexandra Stakes over nearly 2 miles 6 furlongs. Logical so far.

    2. Calculate the average time for each distance. 

    2. Calculate the average winning time by distance and by class. So as an example for 6 furlongs there were 8 races at class 1 with an average time of 73.73 seconds, class 2 was 74.03 seconds and class 3 was 75.13 seconds. Convert these into seconds per mile.

    3. For each race subtract the winning time from the average for that distance and class.

    4. Calculate the average for that meeting. This is the going allowance for that meeting. The highest adjustment (1.53 secs / mile) was in June when the going was good to firm, the lowest adjustment (-2.85 secs / mile) was in October when the going was good to soft.

    I disagree to a certain extent with Mr Mordin at this stage, he takes a subjective view of each meeting, in an example of a 6 race meeting he excludes one race because it was "probably won by an exceptional horse" and for 2 others he excludes them because he would "guess that they were slow-run affairs". That leaves him with just three races to calculate the going allowance.

    5. Subtract the going allowance from the winning time.

    6. Subtract the adjusted winning time from the average winning time for that distance. The highest figure was for Pyledriver in the King George VI and Queen Elizabeth stakes. Intuitively this feels right. The winning time was 149.49 secs (100.00 secs / mile), the average winning time for that distance is 102.62 secs / mile. The going adjustment for that meeting was -0.10 secs / mile, giving Pyledriver a rating of +2.72. The lowest rating was Oh This Is Us in a class 3 classified stakes with a rating of -3.87.

    7. Convert the ratings to a scale. Not strictly necessary but conceptually better. The top rated horse could be given a rating of 140 and the lowest 0, possibly as a comparative to the BHB official ratings.

    8. Calculate the ratings for the remaining horses in each race. I will use Nick Mordin's assumption that every fifth of a second is counted as one length.

     

    So there it is, my starter for ten. It seems logical but I may be missing something. The next step is to calculate these numbers going back a number of years for Ascot and also for all other courses. Time consuming but doable using Excel. Hopefully the effort will be worth it.

     

     

     

    xG - Any use from a footy betting perspective?

    in Footy Chat & Banter

    Posted

    From what you say it would appear to be a good sign if the XG is better than the actual.

    I guess you would only know after you had kept some stats.

    I've always avoided the goals market because the overall overound is so high but you seem to have the football knowledge to overcome that. Unfortunately I don't have that knowledge, I am driven by the stats.

    SPEED RATINGS

    in At The Races - Racing Forum

    Posted

    6 minutes ago, calva decoy said:

    How do you take into account a national hunt chase race where for instance 2 horses of the 8 entered in their last run only jumped 4 of the 8 fences due to a low sun compared to the other 6 who jumped all of the 8 fences & say over a 2 mile trip ? 

    Whatever the answer it'll turn out to be a false narrative because of the 25% from the last runs inequalities & being speedier because of the less jumping needed .

    The only time I used speed figures is via Equibase in US dirt sprint races between 5-6f & it's been quite productive along with low draws in those races but , each to their own & a good thread for discussion 👍

    I think I'll concentrate on the flat, there are enough question marks there !

    SPEED RATINGS

    in At The Races - Racing Forum

    Posted

    22 minutes ago, harry_rag said:

    Thanks, one of those things I do occasionally then forget how to do! In reality it turns out I missed out on 55 bets that showed a profit of 0.4 points to 1 point level stakes so I could have backed 110 bets with an ROI of 18% but instead backed 55 with an ROI of 36%! Obviously we’re into tiny sample size territory there. Overall the indicators support the change I was thinking of but the impact in terms of additional bets will be much smaller than I originally thought.

    With my AW systems last year I had plenty that had shown profits in the "test" year and therefore I could use live. I ended up with loads of selections and overall made a loss.

    This year I have used the system that had the highest p value and I have ended up with much fewer selections but a substantial profit.

    SPEED RATINGS

    in At The Races - Racing Forum

    Posted

    5 hours ago, harry_rag said:

    Wish I could find anyone else to talk about a ratings system for goal (or try/touchdown) scorers but I'm more or less ploughing a solo furrow with that one, barring a guy I used to work with who is effectively my "colleague" in the endeavour.

    Slightly obvious question (maybe) but I'll ask it to see if any of you fellow stats nerds think differently.

    I've started afresh with my data since the new "one spread firm" era began in November and made a slight tweak to my formula to allow for there no longer being two firms offering prices. T'other fella has carried on as before. Doing it his way gives 573 bets with a profit of 37.27 points and an ROI of 6.5% while my new approach gives 414 bets and +29.26 points with an ROI of 7.07%. Those are qualifying selections from an overall data sample of 2348 players.

    So I "win" in terms of having the better ROI but have passed up 159 bets with a profit/ROI of 8.01 points and 5.04%.

    Would you start backing those selections immediately or stick to the slightly less bets/better ROI criteria for a while longer and see how the data develops. The 159 bets is still a relatively small sample size.

    I would calculate the probability value (you need to know the average odds for this)

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