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Ratings2Win - Understanding Speed Performance Ratings
UNDERSTANDING SPEED PERFORMANCE RATINGS (SPR)
Speed Performance Ratings (SPR) can be described as an indicator of relative (recent) ability. An understanding of SPR involves much more than a comparison of overall race times. The DNA of SPR Whilst the following individual factors aren't in isolation anything new, combined they hold the key towards a better understanding of the value of knowing what a SPR is, so that you can more accurately peg a horses ability. The four important factors are: 1. Early speed; 2. Sectional times; 3. Peak speed; and 4. Overall race time SPR in isolation are: • not designed to reliably predict the likely outcome of a race; and • not designed as an indicator of likely market prices/rank. It is important to note that in some races, the predictive SPR will, for the most part be inaccurate when measured against market expectations and/or actual results. These inaccuracies can be either positive or negative and it is for this reason, that SPR should not be taken at face value or considered in isolation as an indicator of the likely outcome of a race. Rather, with a thorough understanding of the DNA of SPR and its components, SPR can be considered as a unique method of comparing race horses, many of which have not previously competed against each other or raced at the same tracks and/or distances. SPR fall into two categories: • Historical (assigned to each historical run); or • Predictive (an SPR derived from a historical run using a unique algorithm that is then used to compare against other competitors) Historical SPR The race winner’s time is adjusted using a complex algorithm for a range of factors including track condition and other proprietary factors before being compared with a ‘par’ time for that track and distance. The SPR calculated for each historical run is a numerical value that is firstly assigned to the winner of each race. For the purposes of this article and for Axis software users, consider 2 rating points as one length. For those individuals that create, or for organizations that supply ratings, that are derived from the standard publically available form (other than R2W), a Rating of 104 for a race winner could indicate any one of the following: • the winner ran a time that (when adjusted) was equal to or faster than the par time; • the official time was incorrect; • the distance of the race was shorter than the official distance; or • the prevailing conditions caused faster times (e.g. wind factor, track surface). Conversely, a Rating of 86 for a race winner could indicate any one of the following: • the winner ran only as fast as it needed to (to win the race) • the winner ran a very slow time (relative to ‘par’ and/or other races on the day); • the official time was incorrect; • the distance of the race was longer than the official distance; or • the prevailing conditions caused slow times (e.g. wind factor, track surface). In summary the Axis SPR assigned to each historical run can be considered an accurate and comparative measurement of how fast a horse ran (relative to par) on that occasion after adjustments have been made. SPR Scale Fast performances = high SPR Slow performances = low SPR The SPR for all other runners in a race (other than the winner) is derived from the rating assigned to the race winner before being downwardly adjusted for beaten margins. Logically because horses run at a faster speed over 1000m than they do at 2400m, the incremental adjustment is less as the distance increases. Again I suggest, for the purposes of explanation, that you can assume an adjustment of 2 rating points as being equal to 1 length. E.g. If a race winner gets an SPR of 100, a horse beaten 2 lengths would get an SPR of ~96. Predictive SPR Within Axis, a complex algorithm selects a historical SPR that is then assigned as a run that is representative of each horse’s current ability and likely fitness level. That run is called the qualifying run (QR). The R2W SPR algorithm encompasses the following assumptions: • high ratings can’t be produced by unfit horses; • recent form is far more reliable as an indicator of current ability and likely fitness that older form; • generally speaking, trainers will place their horses to the best advantage; • horses that perform well when resuming from spells will generally continue to do so up to the age of around five; and • importantly a good rating can be discarded as an indicator of current ability and fitness after approximately 42 days. Having selected an appropriate QR, the SPR algorithm then assigns that numerical value to each runner as a Base SPR. This is then interrogated by the R2W computer before determining whether any adjustment is warranted. Once this process is complete the predictive SPR is displayed in the field view of Axis. Caution needs to be applied to races that are run in fast times As has been explained above, races run in fast times (relative to par times) produce high ratings. However, it does not always follow that all horses that run a fast time, and therefore generating a high SPR will subsequently ‘run up’ to that performance at their next race start. However, it is true that horses that can run genuinely fast times, particularly in good class races, have more ability than other horses they may race against in future. Why R2W SPR are more accurate than other commercially available ratings Without going into too much detail and to preserve our unique IP, R2W SPR are adjusted for the many errors that exist in overall race times, sectionals, distances, track conditions, class of race etc. We outsource to a private organisation that caters to our specific needs and those of some of Australia's biggest and most successful punters. As a guide it is fair and accurate to suggest that more than 90% of official race and sectional times reordered in Australia are incorrect and contain errors that are often significant. Being able to deliver SPR that are adjusted for these errors is one fundamental reason as to why we and our clients are able to maintain and enjoy a profitable betting edge. No other software provider that we are aware of provides the total solution to this problem, that is for ALL TAB races Australia wide. |
Great post. Its great to read through your postings.
Its good to se the detailed explanation of what you use and why. |
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