My earlier post above made the point that weight changes must be considered in the context of the class of opposition a horse is racing against.
Stats show that horses rising in weight win more than horses falling in weight, but that doesn't mean you should treat a weight increase as a positive or negative factor in your handicapping.
Weight changes up or down offer no value from a handicapping point of view without consideration of class, or for that matter other factors like fitness, distance etc. (as EI pointed out in his post).
I have spent quite some time researching and writing about various racing topics and following are the outcomes of my own previous analysis and thoughts on these issues which I am happy to share and invite your comments on:
INTRO
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I examined weight carried changes for runners in three categories:
* -1kg to +1kg on last start i.e. much the same weight.
* 1.5kg and greater increase
* -1.5kg and greater decrease
Of course there are multiple groupings one could use but to demonstrate the principles of weight and class these three groupings are more than suitable.
Along with weight increases, changes in class from the previous race were considered:
* Much easier class
* Moderately easier class
* Much the same class
* Moderately harder class
* Much harder class
These judgements were based on grouping of the class values assigned to each race in the database I use for my racing activities. This database covers every single TAB meeting held in Australia but as in my previous post, the data used for this work was all Metro races in NSW, QLD, VIC and SA over 3 years.
WEIGHT CHANGE STATISTICS
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Overall stats for weight change in the groupings used are:
* -1.5kg's or more = 7.6% SR and -23.1% POT
* -1 to +1 kg's = 8.7% SR and -17.9% POT
* +1.5kg's or more = 12% SR and -20.6% POT
As statistics show, horses rising in weight win more than horses falling in weight. However the significance of weight change doesn't become meaningful until we consider class change as well.
HORSES FALLING IN WEIGHT 1.5kg's or Greater
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Following are stats for these horses according to their class change:
* Much easier class: 9.7%SR and -10.7% POT
* Mod easier class: 9%SR and -18.9% POT
* Much same class: 8.1%SR and -24.9% POT
* Mod harder class: 7.8%SR and -25.3% POT
* Much harder class: 6.6%SR and -23.5% POT
Overall: 7.6% strike and -23% POT
Interesting?
HORSES RISING IN WEIGHT 1.5kg or Greater
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Following are stats for these horses according to their class change:
* Much easier class: 13.5%SR and -16.7% POT
* Mod easier class: 12%SR and -23.5% POT
* Much same class: 11%SR and -13.8% POT
* Mod harder class: 8.1%SR and -25.1% POT
* Much harder class: 4.7%SR and -58.9% POT
Overall: 12% SR and -20.6% POT
DISCUSSION
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Remember that overall it is supposedly a positive factor that a horse is rising in weight and a negative one that a horse is dropping in weight.
Excluding profit for the minute, weight droppers only have a 7.6% strike rate, yet weight risers have a 12% strike rate.
But weight risers racing in moderately harder class only have a 8.1% strike rate and a shocking 4.7% strike rate when racing in much harder class. How then can a weight rise by itself be a positive factor?
Weight droppers who are going to race in moderatelly easier class have a 9% strike rate and if in much easier class a 9.7% strike rate, better than certain horses rising in weight. Again, how can a weight change by itself be considered a positive or negative factor?
HORSES WITH MUCH THE SAME WEIGHT -1kg to +1kg's
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Following are stats for these horses according to their class change:
* Much easier class: 11%SR and -13.7% POT
* Mod easier class: 10%SR and -22% POT
* Much same class: 9.5%SR and -23.5% POT
* Mod harder class: 8.4%SR and -21% POT
* Much harder class: 6.5%SR and -17.9% POT
SUMMARY
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A quick glance at these figures shows that we can make no conlusions about weight change that have any valid meaning to our work as form analysts and punters. Irrespective of weight, horse going up in class have a significantly inferior record.
Some people claim that rising in weight is meant to be a positive factor yet the worst profit figures from this analysis come from horses rising in weight who are racing in moderately harder or much harder class. Quite ironically the next worst comes from horses who are falling in weight that are racing in harder class.
This leads me to believe that the market "underestimates the importance of class" and therefore overestimates the winning chance of horses racing in harder class. Also implied is an overestimation of the impact of weight, particularly decreases in weight when a horse is rising in class.
While simple statistics by themselves cannot offer us any winning advantage, there is no doubt that as an analysis principle, CLASS is KING. As Pitsburgh Phil said, "show me the man who can class horses correctly, and I will show you the man who can make all the moeny he wants."
I advise anyone looking to build a reliable and successful form analysis process to focus on class as the primary element.
Some of my views on class were featured in Neils latest edition of Punt to Win, if you haven't already you can read more at:
http://www.propun.com.au/betting_advice.html
Needless to say I focus on class myself and determine it primarily through speed and pace, which with the assistance of good technology and racing intelligence offers me a legitimate and tremendous winning advantage.
Please feel free to pass on your thoughts and comments. Discussing topics like this where we can all learn something from each other is what forums should be about.