A spectator at a chess tournament.

someone who gives good advice to your opponent and bad advice to you.

A non-playing spectator; a railbird.

A spectator at any game who has a habit of looking at active players' cards and dispenses unwanted comments and/or advice.

A spectator, usually unappreciated by the players

a spectator of card games, as opposed to an active player. Other slang terms for this person include goose-necker, yahoo, yokel or railbird

A spectator at any game who usually dispenses unwanted advice.

A commenting spectator.

To give unsolicited racquetball advice during a course of a game, from Yiddish-Russian.

A spectator who often offers unwanted advice or comment.