Real-time leaderboards: Should we poll or use WebSockets?

so, i'm building this real-time leaderboard thing for a game, and i'm trying to figure out the best way to update scores. should i just keep polling from the client a lot, or should i go all-in with WebSockets for actual real-time pushes? have you guys dealt with scaling either of these for tons of users at once? any weird problems i should watch out for