Nap Of The Day. Catterick – Project Bluebook. What is a NAP of the Day? A NAP of the Day in Horse Racing is a Tipsters best bet for that days racing. THE CHELTENHAM FESTIVAL will see thousands of horse racing fans flock to the famous race course in search of winners - so here are all the. A tipster is someone who regularly provides information (tips) on the likely outcomes of sporting Tipping is mostly associated with horse racing but can apply to any sport that has odds offered on it. Rather than pick a tip for each race that occurs on a given day the normal protocol is to provide a Nap and nb selection.