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You must stay on top of changing draw bias
I still love betting in sprints, but as I have said many times over the past two or three years it is becoming harder and harder. The reason this is the case as far as I am concerned is simple - draw bias is diminishing at some courses and difficult to predict at others. The draw bias factor has always been a strong weapon in my punting armory and most of my best bets have consistently come from using draw bias in one form or another. It may have been the course in question on the day, or it may have been down to the horse running from a poor draw in the recent past. This avenue of good bets though is steadily decreasing, but the key is to stay one step ahead of the crowd. In the past knowing draw biases was crucial – now it is just as important to know where bias is diminishing or changing. If you can appreciate the changes then value bets pop up elsewhere – for example, if a high draw bias does not exist any more, but the general consensus is that it does, then horses that are not drawn high suddenly become value prices.
Let us look at a draw bias that has diminished in recent years. The course in question is Hamilton and I am concentrating on the straight course at the Scottish venue. On the straight course at Hamilton they race over both sprint trips of 5 and 6 furlongs. When analysing each race, I have divided the draw into thirds - those drawn in the bottom third, those drawn in the middle third, and those drawn in the top third. On a completely fair course the winning percentages for each "third" of the draw should be around 33% each. The differences in the percentages will determine the strength of the bias. I consider there to be two types of draw bias. Firstly, clear bias towards one specific third of the draw - this is the strongest possible bias. Secondly, you can get a bias against one specific third of the draw.
The data for this article is taken from 1996 to 2007 and only include races of 10 or more runners. For bias to exist there needs to be a reasonable amount of runners and 10 or more runners is the figure I have always used. Draw bias is far more likely to be prevalent in larger fields as horses will either be forced to run wide (hence having further to travel), or be forced to run on a slower part of the track (usually the unfavoured rail).
Let us first look at the Hamilton draw stats for 5 and 6f races from 1996 to 1999 (10+ runners):
The picture is already starting to change. High draws still had an advantage during this period, but the bias had become far less strong. Indeed, let us look at the above 5 positive points from 1996 to 1999 and see what would have happened using the same approach in 2000 to 2004:
a) 15.5% of all the races were won by one of the horses drawn from the two highest numbered stalls. Compare this with the lowest two draws who won 11.2% of races.
Quite a turnaround – during this period there was virtually nothing in the highest two and lowest two draws. From 1996 to 1999 the highest two draws produced over 7 times more winners. From 2000 to 2004 that figure was down to 1.4 times.
b) If, in every race, you simply placed 1 point on the highest numbered stall, you would have made a massive loss of 76 points (ROI -65.5%).
So a 100% profit on turnover has become a loss of over 65% … ouch! All 1996 to 1999 profits had been wiped out.
c) If, in every race, you simply placed 1 point on the second highest draw, you would have made a loss of 1.5 points (ROI -1.3%).
Only a small loss, but still a massive turn around from the 1996 to 1999 figures. The returns would have been considerably worse but for a 33/1 winner during this period as well.
d) If, in every race, you permed the 3 highest draws in six 1 point straight forecasts, you would have made a substantial loss of 304 points (ROI -43.7%).
A 437 point profit from 1996 to 1999 has become a 304 point loss from 2000 to 2004. This would have been quite a dent in your winnings if you had used this bet from 1996 to 2004. To see around 70% of your 437 point profit wiped out would have been hard to take. Hopefully you would have noticed the changing trend and stopping betting on them!
Hence the draw bias picture had changed markedly in terms of using the Hamilton draw for profit making purposes. All previous profitable angles were now non existent.
To complete the picture let us look at the draw stats for the last 3 full seasons (2005 to 2007):
We now have a situation where there has been no consistent bias over the last three years and hence the halcyon days of Hamilton high draw bias look well and truly at an end.
The question you may (or should) be asking is why? How have things changed so markedly? Essentially there are three main reasons:
i) the position of the stalls have changed considerable since 1996. Between 1996 and 1999 the stalls were either positioned high (far rail) or low (stands’ rail). Indeed, the majority of races saw the stalls placed high (around 70%). Hence high draws were drawn next to the far rail whereas low draws were stuck out in the middle (unless there was a near maximum size field). At most courses, and Hamilton was no exception, the ground closer to either rail was quicker than the ground down the middle. From 2000 to 2004 there was a change in policy and 65% of races saw the stalls placed low, with 34% placed high and 1% placed in the centre.
Since 2005 there have been just 2 races with the stalls placed high. The remaining 153 races have seen 80 races with the stalls in the centre and 73 races with the stalls placed low. As the stats above show the last 3 seasons has seen a level playing field in terms of the draw and moving away from positioning the stalls high has been a significant factor in this change.
ii) the second reason for the change is the fact that Hamilton have been guilty of over watering the far rail (high) in an attempt to slow the quickest strip of ground down. Hamilton is not the only course who have employed this tactic in recent years either.
iii) finally, Hamilton course officials have occasionally moved the far rail in a few yards. This means that the quickest strip of ground is now the wrong side of the rail.
These combined factors have seen the end of the high draw bias at Hamilton. Indeed the early signs of 2008 seem to suggest that a low draw bias is beginning to develop. If this is the case then we must take advantage of this before steps are taken!!!
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