I used to buy the Sportsman for many years and long term, Zip form is no better that what tipsters come up with in the newspapers. Backfitting Zip form result for 1 good Sat. and working out what they produced best with this or that rule, doesn't really tell you anything. It's been backfitted to results. The same thing could be done for any number of results for various Saturdays from any number of sources [including newspaper tipsters].