strategy
Tell
Also: physical tell, timing tell, bet-sizing tell
Any unintentional behaviour that reveals information about a player's hand: a glance at chips, a change in breathing, how quickly they act, or how they size a bet. Live tells are famous; timing and sizing tells exist online too.
Example. Every time he glanced at his chips after the flop he had connected — a classic tell.
Reliable tells are rarer than television suggests. The most durable ones are 'timing tells' (instant calls usually mean draws or medium hands; long tanks followed by a raise are rarely bluffs) and 'sizing tells' (a player who bets bigger with bluffs or smaller with value). Physical tells vary by player and should be confirmed before trusting them.