What does it mean when you are sweating someone on the rail?

Question

I know it has something to do with poker. Please Help!

Answer 1

The rail is the poker term for the spectator area. Non-players and people already knocked out of a poker tournament are said to be on the rail.

You might be sweating someone from the rail if you have lent them money to participate in a tournament and you are watching them play with a vested interest in their results. You may be in the same position if you are a teacher watching a student play.

So in simple terms it would be being a supporter for a specific player while spectating.

Answer 2

To add on to ZCT's point: more generally "sweating" someone just means to watch them play poker. The "rail" is a term for the area just outside the gambling pit. Thus, you're watching someone play cards from outside the gambling area.

While this terminology developed due to they layout of the casino, it is used to describe online play as well. For example, I sometimes log on to a poker site to watch when a friend of mine is at the final table of a tournament. They refer to this as "sweating," and the players doing the sweating are referred to as "railbirds."