MORNING LINE FAVORITES
The primary task of the morning line maker is to assist the betting public by predicting the final odds at post time. The construction of the morning involves both the ordering and quantification of the odds of each contender. One of the best measure of the skill of the line maker is how often the morning line favorite goes to post as the favorite.
We will look at results of approximately 50,000 North American parimutuel thoroughbred events for the last 360 days prior to today (11/23/2009).1
15,879 of the 49,665 morning line favorites went onto win their races at a strike rate of 32%. Remember, this is not the success rate that we seek to measure. While it is valuable to see that favorites did indeed win a significant portion of their races, we want to assess the linemaker and not the favorites. Of the 49,665 MLO favorites, 33,300 became the PTO favorites. In other words, in a little over two-thirds of the time, the morning linemaker successfully identified the favorite.
Situationally, the morning linemakers can identify post time favorites more frequently than the standard race. With short field sizes, one would anticipate linemakers would have a great success at identifying the actual PTO favorites. When restricting the sample of races to 5-horse fields or smaller, 2,160 favorites were correctly spotted in the 3,009 morning line favorites. The success rate of pinning the tail on the favorite jumped to 71.7%. Unfortunately, the typical field size in North America spans from 6 to 9 horses inclusively. The success rate drops to 67.4% (22,252 actual favs from 33,039 morning line favs). In large fields, one would expect the correct labeling of the favorite to occur even less often. Of 13,786 morning line favorites in 10+ fields, 8,997 went on to become post time favorites at a strike rate of 65.3%.
In the future, we will investigate other situations in which the linemakers succeed and fail in identifying the posttime favorites.
1. While every effort has been made to insure the accuracy of the statistics provided above, the author assumes no risk on the reader's use of the information. As with all financial markets, past results do not guarantee future performance.
(2009.11.23 -- sps)