Coat-tail is a gambling term most often used in land-based casinos; it refers to a person who is betting the same numbers as the person winning at that moment.
Needless to say, a lot of casino players are quite superstitious. When you combine that with long losing streaks, it doesn’t come as a surprise that those players are quick to decide it’s time to change tactics. While some simply change their approach and bet different sets of numbers or amounts, other players bet the same numbers as someone who’s been winning throughout the night.
Coat-tailing is most often used by inexperienced players, especially at roulette tables. However, it’s not uncommon to see a good player on a losing streak try someone else’s numbers. Sometimes, they might follow someone else’s example, even if it’s for the sake of breaking their unlucky streak before continuing to bet their usual way.