In this article, provided by the respected UK website Flatstats (www.flatstats.co.uk), some pertinent points are made about the effects of weight on racehorses. The article refers to British racing but can be related strongly to Australian/NZ racing. PPM's Richard Hartley Jnr offers some comments on the article as well.
Do you believe that weight is an effective tool for controlling the performance of a horse? Do you think a horse going up 10lb (5kg) in the weights has less chance today than last time?
Weight is one of the great racing conundrums. How can a few kilos extra on the back of a 1000lb (500kg) thoroughbred influence its performance?
Weight is used to handicap a horse's chance of winning. The more successful the horse, the more weight it carries and the less successful it should be in future races.
At the other end, poor horses are allowed to carry less weight and thus should better their recent finishing positions.
The handicapper has the task of assigning ratings for every horse that runs at least three races. But how accurate are his ratings? Like anyone who compiles weightadjusted ratings the figures are going to be complicated by incorrect going descriptions and different course topologies such as those which favour topweights.
The following statistics should shed some light on how much of an effect weight has on a horse. First we will look at the performance of horses carrying more or less weight than their last race, next the performance of the handicapper, and finally the effect of extra weight influences such as overweight, penalties and allowances.
The first figures show the results of 221,644 runners on the UK turf since 1993. Horses carrying more weight than their last race won 10.22 per cent. Horses carrying less weight than their last race won 8.63 per cent. This means a horse carrying more weight than last time is 1.19 times more likely to win than one that is carrying less.
Obviously, this is looking at all turf races and does not take into account horses going up or down in class which will have a bearing on the allocated weight.
With turf runners in the same class, 38,120 carried more weight and 3925 won, a strike rate of 10.3 per cent, while 40,950 carried less weight and 3630 won at 8.86 per cent.
The figures are pretty much the same as in all races. Horses carrying more weight than in their last race, which was of the same class, won more than those carrying less.
With horses racing in a handicap who raced in a handicap last start, there were 50,031 runners and 5474 won at 9.95 per cent, while 57,085 carried less weight and 4217 won at 7.39 per cent.
These stats examine handicap races where the last race was a handicap, too. Although the strike rates are lower, the index at 1.35 is bigger, indicating that a horse that is rising in the weights is progressing in the right direction.
With horses racing in a handicap today and who raced in a handicap in the same class last start, a total of 20,108 carried more weight and 2092 won at 10.4 per cent, while 22,380 carried less weight and won 1658 at 7.41 per cent. This gives an index of 1.40, and shows that weight-rise handicappers running in the same class have a big advantage.
With turf runners in stakes races (non-handicap), 36,323 carried more weight and 4268 won at 11.75 per cent, while 39,751 carried less weight and 4665 won at 11.74 per cent. This indicates that weight change in stakes races has no effect.
The next figures are interesting in that they are the only ones where it is an advantage to be carrying less weight. This is when horses are in a handicap today and raced in a stakes last start. A total of 10,155 carried more weight and 1035 won at 10.19 per cent. Yet 11,093 carried less weight and 1412 won at a higher strike rate of 12.73 per cent.
With horses in a handicap today and last start, and racing on similar going, a total of 6046 carried more weight and 713 won at 11.79 per cent, while 6710 carried less weight and 511 won at 7.62 per cent, giving an index of 1.5.
As higher-weighted horses win more on firm ground and less on soft ground, we want to be sure that changes in going are not causing spurious results. The weight-rise horses have a much bigger advantage when the going is the same.
And now to a few words on handicapping. The race handicapper has a tough task. He has to allocate a rating for every horse that runs. His task is to assign a rating such that all the runners in a handicap will finish in one big dead heat. This has never happened, and probably never will.
The following table examines his performance over the years and shows the average winning distance that the winner beat the second-placed horse. If the handicapper were to be 100 per cent accurate the figure should be 0 as we would expect to see a dead heat.
We will look at all handicap races run on good ground only. This is to ensure the figures are not influenced by soft or firm ground.
Over the past five years the average distance between the winner and the second horse has fallen steadily from 1.7 lengths to 1.4 lengths. This can mean one of two things. Either the quality of horses in this country (UK) is getting better, or the handicapper is becoming more accurate.
We suspect the latter. The handicapper is sure to be utilising the advances in technology which enable him to rate faster and more accurately. Like the world record for the 100m, sprint, will the average winning distance ever reach zero?
Richard Hartley Jnr comments: The statistics in this article make most interesting reading. Later on in the year, PPM will present some decent odds.
Let's take the case of Matter Of Honour at Flemington on February 15. This 6yo had won at Randwick over 1100m on January 18 carrying 61.5kg against a Limit of 53kg. This was some 8.5kg over the minimum. He won that race by 1.5 lengths.
Trainer Paul Perry then took him to Melbourne and put him in the Listed 1400m Chester Manifold Stakes. Now, in this race he was set to carry 54kg on a 52kg Limit. So, in effect, he was dropping 7.5kg in actual weight and went down from figures relating to Australian racing on this very same subject.
Most of us wrestle with the problems of the handicapping of a race. We see horses set to carry more weight than last time and we worry about it. Yet are we worrying too much? The UK stats seem to indicate we are.
Why does a horse get more weight? Usually, for GOOD form or for DROPPING in class. If a horse is racing well, and winning, it is probably capable of carrying extra weight to a certain point. The punter's task is to decide at which level this 'break' line is reached.
Is it 57kg, 59kg, 60kg or more? Can a horse cop a 3kg or 4kg rise, even if dropping in class? Can it cop that sort of rise in equal or higher class? The conundrums go on and on.
For myself, I've always been a sucker for the horses that DROP a lot in weight from one race to the next. I love it when, in a good race, especially Listed and Group handicaps, I see a well-performed horse dropping 5kg or more in the handicap. They often win at very lugging 8.5kg over the Limit at Randwick to carrying only 2kg over the Limit in the Manifold.
That weight turnaround was enough to help him win the race at good odds. Another example of a weight-drop winner is Athelnoth, who won the Group 2 Royal Sovereign Stakes over 1200m at Randwick on February 22.
The 3yo ran 4th at Randwick on February 8 and had no luck, ending up beaten 1.3 lengths by Vital Agreement. In that race he carried 58kg on a Limit of 53kg, meaning he had 5kg over the minimum. In the Royal Sovereign, at set weights, he had 54kg, the minimum. SO, he dropped 4kg in actual weight, and 5kg when you compare his task at Randwick on February 8 with his task in the Royal Sovereign.
Athelnoth scored and paid more than 16/1 for the win, an excellent return.
These are a few thoughts, then, on weight. Take careful note of the UK statistics as I feel they may well be closely replicated here in Australia.
By Flatstats UK
PRACTICAL PUNTING - APRIL 2003