Weight Handicapping and Ratings (part 2)


\Wizard Daily Report and Research - Tuesday, 12 December 2023.

  • Weight handicapping and ratings (part 2)


Relative Weight Ratings - After the race

The rating of a race takes place before the running of a race, and for the Wizard, after the race as well.

It is easy to understand why you would rate a race before it is run; after all, you are looking to see which horse/s might enjoy a relative weight advantage and rate as a possible winner of the race.

But why after the race?

The fact is, before race and after race rating are equally important.

The quick and easy way to do the re-rating after the race is to rely on a formula that automatically calculates the rating run by each horse. The problem is, to as accurately as possible, address the actual quality of the race.

I have seen various approaches taken that involve weighting the final rating by the quickness of the time run, by the number of runners finishing within 3 or 5 lengths of the winner, by the margin between first and second, by the prizemoney, etc. None seemed satisfactory to me.

The approach taken by me, and Don Scott, quite independently of one another, is to examine each race on its own merits, and adjust the base rating to reflect the quality of the field with reference to each horses ratings and racing record.

This takes time and effort. For example, last Saturday there were 22 meetings run in Australian and New Zealand. That meant re-rating for quality-assessment purposes 160 races.

What is entailed in this Wizard re-rating process?

What follows is an illustration, by way of an example, from the meeting at Randwick last Saturday.

Before we start the discussion of this re-rate, an explanation of the columns. (Note: On my re-ratings screen I do have more detail but what is shown here covers the main elements considered during the re-rating process.)

The full field is not shown as the re-ratings process focuses only on horses which finish within 6 lengths of the winner.

The columns:

Horse              Horse name

Mgn kg            Beaten margin kilograms

ExPk               Expected Peak rating

CuPk               Current Peak rating

BL3                  Best rating last 3 starts

Chg                 Difference between BL3 and projected rating for this race

Rating              Rating earned in this race

Prev                 Last start date, 1st or beaten margin, class, rating

Prev2               Two starts back date, 1st or beaten margin, class, rating

Prev3               Three starts back date, 1st or beaten margin, class, rating


Randwick 9.12.23 Race 9 BM 0-78 
Horsemgn kgExPkCuPkBL3chgRatingprevPrev2Prev3
ZOE'S PROMISE0.047.045.545.5+1.046.51811  0.4  78  45.50411  2.7  78  42.02005  5.6  fm  36.5
MISSY MOOLA0.839.040.540.5+4.044.51811  2.7  78  40.52405  48  78  10.01005  3.5  c2  36.5
ARISTONOUS1.045.0fu44.5+1.546.00508  4.8  78  41.50807  3.2  78  42.52406  1st  72  44.5
DEFICIT3.046.041.545.5-1.544.02511  2.9  88  39.00711  2.7  88  41.50107  1.8  78  45.5
ITA3.347.039.044.0-0.543.51811  3.8  94  39.02907  4.6  78  42.51507  2.7  78  44.0
PROMITTO5.637.043.543.5-1.043.51811  2.7  78  43.50911  6.4  op  37.52110  4.4  88  41.5
BIANCO VILANO7.547.042.542.5-4.037.52411  2.8  po  41.00711  2.5  op  42.51410  15  sw  29.0
THE DRAMATIST7.543.044.544.5-8.536.01111  1st  c3  44.52810  1.9  c3  44.52003  1.8  c5  40.5


The race to be discussed is a BM 0-78 race run at Randwick on Saturday, 9 December 2023.

This race is pretty typical of race where all/most of the runners have recent form.

When re-rating a race for quality-adjustment purposes, my frame of reference includes the horses expected and current peaks, as well as the best rating in its last three runs.

When deciding on the overall race adjustment I ask myself how does the projected rating for each horse compare to these key ratings. Has the horse registered a new career peak (compare with expected), is the run good enough to improve on anything done so far this preparation (compare with current), and how much better/worse is the projected rating compared to the best rating in its last 3 starts?

Zoes Promise Has an expected peak of 47.0, and a current peak of 45.5, with the current peak being the same as BL3 runs. So, on the best of the last three starts she goes into the race 1 length (1.5kg) off her expected peak. Here she should have improved on that BL3, but by how much? The field was not overly strong, only 2 wins had been registered by the 7 horses which finished within 6 lengths of her in this race (that is, 2 wins from those 21 runs). The race adjustment I used for this race has her rating 46.5, which is 1kg (2/3 length) better than her last start when she was beaten 0.4 lengths, about 0.5kg, in a similar BM78 race, and still allows her to improve before she reaches her expected peak. The field strength and close finish of the placegetters were factors in this decision.

Missy Moola Her current peak and BL3 exceed her expected peak, and her BL3 was at her last start. In that last start she rated 40.5 and was beaten 2.7 lengths in BM78 race, so if she had won that race would have rated 44.5 (2.7 x 1.5kg = 4kg). That was her second run from a spell, and she is trained by Gai Waterhouse and Adrian Bott, whose horses can improve more than the typical runner from other stables. Had no trouble allowing her to improve 4kg and run a 44.5 here as two preps back she had run a WFA adjusted rating of 44.5kg in New Zealand.

(I have found that the race winner will normally race 2kg to 2.5kg better than their BL3. If the field beaten is not quite as strong as normal, then it will be an improvement of 1kg to 2kg. There are stables, Gai and Adrian for example, whose horses will improve 3kg to 4.5kg from their BL3 when they win off placed or unplaced form, though not off winning form.)

Aristonous This 5yo is trained by Annabel Neasham and is an import from France, resuming from a spell, who won at his first race start in Australia. This is his second preparation here and it is commonplace for these imports to improve sharply in their second local prep. He has an expected peak from the first Aus prep of 45. The race adjustment I used for this race has him rating 46 first up, better than his expected peak, and that seems reasonable given his background and his trainer, who I regard as one of the real emerging training talents here in Australia.

Deficit  This 5yo gelding was coming off two stronger BM88 races and was having his third run from a spell. In these two races since resuming he rated below his expected peak (the BL3 rating was the last run in his previous prep). His best form seems to be around his 5th run in, so I would not expect to see him hit a peak on this occasion but feel comfortable with him improving on his recent form. The race adjustment I used for this race has him rating 44 and I expect he could have another two lengths (3kg) improvement to come, but that sort of improvement was not warranted in this race. In fact, in June last year he ran a WFA adjusted 47.5 and the year before a 48.5. The 47.5 seems possible some time in this prep, so again, 44 seems appropriate given that in this race he was beaten 3kg (2 lengths).

Ita Another having her third run in this prep. Similar circumstances to Deficit. Has an expected peak of 47, and three starts back on July 15 she ran a 44 when beaten 4kg in a BM78. So, if she had won that BM78 she would have rated 48, and here if she had won this race (with the quality-adjustment chosen for this race) she would have run 47 (43.5 + 3.5kg beaten margin) which seemed reasonable.

(Note: I am conservative when re-rating after a race. If you rate too generously you are likely to be backing an over-rated runner for two or three starts based on the generous assessment. If you rate conservatively, you might miss one win but the rating assessment for the horse can quickly correct itself through its subsequent performances.)

These were the main factors considered when deciding on the quality-adjustment for this race.

I think you can see why I said it can be a time consuming process especially when there are 160 races to re-rate for one days racing.

The Wizard relative weight ratings are a key component for race assessment. They provide a reliable and accurate quantitative side of the quantitative-qualitative form assessment equation, and have done so since 1988.

(To be continued.)


Warren - Wiz-Ed

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