THE EFFECT OF WEIGHT ON SPEED RATINGS. Runners Racing In the Same Class I have had a few looks at this subject but have never undertaken a study as detailed as what I am about to report on. Doing such a task in Australia is nigh on impossible with so may tracks and grades but Hong Kong has provided the perfect storm for such research with only 2 tracks and a grading scale a child could understand. It was in Hong Kong where I really first noticed the effect that weight changes were having on ratings and it begged a far deeper study so the following is the statistical results on a study of 30'000 records I have created since I started in HK back in 2011. The first thing I needed to check was all runners staying in the same class with the same weight, this would give us our control, we would obviously expect to see an average of 0 here and the good news is that the 2700 runners staying in the same grade with the same weight had an average rating change of 0. The table below shows a plotted graph with the increadse or decrease in weight down the left hand side and the speed rating difference across the bottom. I have also included the number of samples in yellow writing within the box, for example we have only 18 samples of runners dropping 15 pounds with the average increase in speed rating of 18 points, this is a very small sample and probably not truly indicitive, yet as we we get closer to 0 point our sample depth is more than ample. When plotted in this way the trend is more than obvious, those who drop in weight whilst racing in the same class see an increase in their rating whilst those who have to carry more weight see a drop off in weight see an increase in rating.
If we concentrate on the areas we have over 100 samples there aappears to be 2 trends. Firstly the bigger the weight increase the bigger the drop in rating, we all know that weight will stop a train so this isnt a surprise at all. On the flip side to that coin there does seem to be an obvious advantage in dropping in weight but there was no difference between dropping 3 pounds and no pounds. Again I can make sense of this as it is similar to terminal velocity, a human can free fall from a plane and increase speed until he is falling at 200km an hour, this takes about 12 seconds but once that speed is reached it stays the same until a chute is deployed or until he hits the ground. So with weight we can drop weight to get you to your best but a further drop in weight cannot make you go faster than your ability dictates. So from this I would suggest you can deduct 1 point for every pound a horse rises in weight when racing in the same grade with a maximum penalty of 8 points and a horse will improve 1 point for for every pound dropped with a maximum allowed improvement of 4 pounds. For Australian racing that would become 1 point for every half kilo up in weight with the same maximum penalty of 8 points and 1 point bonus for every half kilo when down in weight.
SAME CLASS 15 14 18 13 12 11 10 9 41 8 7 6 5 67 727 4 135 377 1028 3 163 204 478 1495 SPEED 2 RATING 1 2000 DIFF 0 2011 2736-1 1687 561-2 21 916-3 1325-4 395-5 -6 31 501 314 202 16-7 150-8 28-9 97-10 44-11 -12-13 33 19-14 -15-15 -14-13 -12-11 -10-9 -8-7 -6-5 -4-3 -2-1 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17
WEIGHT INCREASE/DECREASE Runners Rising In Class The next table reflects those runners rising in grade and I suppose the first thing we notice is how few there are with only 1365 runners rising in class and hence the sample sizes are much smaller. The thing that really jumps out at me is that only 316 runners or 23% actually improved their rating despite the vast majority (849-62%) carrying the same weight or less. To make this example even more glaringly obvious 618 or 45% of the runners who dropped 7 pounds or more actually dropped in ratings. Its also interesting to see that those carrying the same weight whilst going up in grade actually rated 2 points less on average. Obviously those who rise in weight as they rise in grade are very few but we have a strong sample of 77 for those rising in grade and 3 pounds with the average drop in rating of 7 pounds, nearly thrice that of those racing in the same grade with the same increase Another little anomoly is that the bigger the weight drop with the class rise the bigger the drop in ratings, this would most probably be explained by those runners that are jumping more than 1 grade and hence the handicapper rates them way down in the weights. Not 100% in what we can deduce from this set of data but it does appear that the class rise offsets the weight drop and if the handicapper thinks enough of you to rise you a pound or 2 you must be a highly progressive type but significant rises in weight and class have a very negative combined effect.
UP IN CLASS 10 9 8 7 6 5 4 25 3 30 2 85 73 SPEED 1 64 39 RATING 0 61 DIFF -1 91 83 16 12-2 84 54 60 56 52 13-3 93-4 -5 103 9-6 92-7 72 77-8 21-9 -10-11 -12-13 -14-15 -15-14 -13-12 -11-10 -9-8 -7-6 -5-4 -3-2 -1 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 WEIGHT INCREASE/DECREASE
Runners Dropping In Class The table below clearly shows that class has a bearing on the ability to reproduce speed ratings better than anyhting and it is in stark contrast to what I have long believed. I used to say that 1 or 2 kilos is meaningless to an animal that was 500kg but data suggests otherwise and the table below shows that class will carry a galloper a long way. If you look at the runners going up 11 pounds or more as they drop in grade you will notice the majority actually improve their ratings, even those going up 20 pounds in weight. There is no glaring trend either way for those dropping in grade and rising in weight but even with only a small set of samples those who drop in class and get significant weight relief can improve their ratings out of site.
DOWN IN CLASS 15 14 13 15 12 11 10 6 9 13 8 7 6 5 4 18 42 3 59 2 35 79 82 100 125 143 SPEED 1 16 93 107 RATING 0 32 DIFF -1 38 34 35 63 126 125-2 57 67 50 68 84-3 67-4 177-5 -6-7 -8-9 -10-12 -11-10 -9-8 -7-6 -5-4 -3-2 -1 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 WEIGHT INCREASE/DECREASE
This really has been a fascinating project and to me shows us some fantastic data but one thing is for certain weight increases and decreases for horses racing in the same grade really does have an impact on a horses future performance Over the next few months I will do further extensice research into the effect of horses rising in weight and distance and those rising in trip off a neg split run. The beautifull thing with the punt as in life, you never stop learning and each and every time we learn something new our markets become more accurate. Nathan and I are currently working on our next version of the site and one thing is for certain we will be incorporating weight adjusted ratings into it. Hong Kong is a lot simpler but there is no doubt with some work we can get a similar model to work for Oz rating.