The Paris Radiogenic Sweepstakes was a lottery organized by Tom Paris aboard the USS Voyager in 2372. For one replicator ration, crew members could try to guess what the radiogenic particle count would be the next day. The winner would take home all the collected rations, minus Tom's 10% "handling fee". If no one guessed correctly, the prize would continue to accumulate.
Chakotay put an end to the Sweepstakes after a few days and confiscated the prize. (VOY: "Meld")
It was later revealed that Paris' insubordinate behavior had been part of an operation to find the Voyager crew member who had been feeding information to the Kazon. (VOY: "Investigations")