Among the handicapping tools that Steve Fierro writes about in The Four Quarters of Horse Investing are filters. What is a filter? As Steve says, "A filter is an isolated/documented factor which determines whether a race is actually playable or not. They are also items which are monitored to determine their impact through record keeping." In other words, a filter is some logical subcategory of your bets. It could be sprints. It could be a certain spot play in a certain type of race. It�s a subset of your total bets, grouped together for some logical reason.
Filters are usually used as negatives � to identify and get you off certain categories of bets that are losing you money.
Steve lists a number of filters that he tracks and uses: Three Overlays Pass, Pass All Too Low, Pass Legitimate Favorite. For instance, the Three Overlays Pass filter is defined as races in which he has three overlays according to his betting line. Using these filters, Steve found that his bankroll was leaking cash in these certain types of races.
A bankroll leaking cash is like a boat leaking water. It�s going to quickly sink unless you find and stop the leaks. For example, Steve documented a five-month period in which his profits were $6, 978. The money he saved by not betting his filtered races was $24,562. In other words, he transformed a situation where he would have lost $17,584 into one where he won $6,978. All from using filters. Do you see how important they are?
Now, don�t run out and start using Steve�s filters. That�s the thing about filters � they�re purely personal and based on your own betting records. What�s negative for him might be positive for you. All of which underlines the absolute necessity of keeping betting records if you�re a serious horse bettor.
With that caveat, here�s a filter I�ve been using lately: Changed Track Condition Today. This filter includes races at a track where today�s track condition is different than it has been for the last couple of days. To me, this is a prime clue that a new causal phase may have started. A changed track condition can often indicate a new surface bias. This could be a running style bias, where certain types of running styles are favored. For instance, horses who get out early might suddenly have a decided advantage. Or it could be a post position bias, where certain posts become superior at certain distances. Or it could be a jockey bias, where some jocks know how to analyze and take and advantage of the off condition, while others just want to get their wet clothes off and go home.
(As an aside, have you noticed how often tracks are cancelling for bad weather this year? I know it�s a bad winter back East, but this is ridiculous. And it seems especially prevalent at "racinos" � tracks that have slot machines and other gambling on the premises. I could be wrong, but I think this may be one of the negatives of slots. Horse racing becomes a sideshow which is expendable because it�s not the mains source of revenue anymore.)
But back to the subject: Surface biases such as these are often hard to prove statistically � they come and go too fast to produce a sample that gives statistical confidence. But that doesn�t mean they don�t exist. "There are more things in heaven and earth, Horatio, than are dreamed of in your philosophy." Even if your philosophy is just the study of why horses win races.
Anyway, my evidence that the Changed Track Condition Today filter isn�t imaginary is my records. Over the last two weeks, the bets I tracked when there was no changed track condition generated an ROI of .96 (minus 4 cents per dollar bet). Not a great period, but that�s the reality for me. However, the bets I tracked when there was a changed track condition generated an ROI of .60 (minus 40 cents per dollar bet).
Any tool that can improve my ROI by 36 cents is one I definitely have to continue to use. Again, a filter that works for me may not work for you. The point is that you should keep your own betting records and use your own filters to plug the leaks in your bankroll. It�s hard to imagine sailing off into financial success at the track without them. NC
Copyright �2003 NetCapper Inc. All rights reserved.