Rule 1: Consider only races run over the distance of 1200m or less.


Rule 2: Consider any runner aged four years and older.


Rule 3: Must have finished first, second or third in its latest start.


Rule 4: Last start must have been 30 days or less ago.


Rule 5: It must have finished out of the first three on at least three consecutive occasions immediately prior to its most recent run (e.g. form figures of 146892 would qualify).


Rule 6: Ignore any race in which there is more than one qualifier.


The website cdsystems.uk.com comments: "Of all the different types of racehorse, perhaps the most prone to alternating sequences of good and poor performance are older sprinters. They can be out of form for a considerable time before suddenly producing one run which sparks a resurgence. This improved level of performance may continue for a short while before the sprinter begins another decline. The secret is to catch these older sprinters just as they hit one of their purple patches."