What is a Lucky 15 system?

A Lucky 15 system consists of 15 bets which transpire from 4 picks. One single bet per pick, six 2-pick multis (parlays), four 3-pick multis (parlays) and one 4-pick multi (parlay). At least one of the four picks must be correct to gain some winnings - the exact amount of the winnings depends on how many of the predictions prove correct.