open-raise

An open-raise (often just "open") is the first preflop raise made before any player has raised or called. It is the most basic and most frequent preflop offensive action.

Detailed Explanation

The open serves two purposes:

1. Take preflop initiative: become the last preflop raiser and gain range advantage and cbet initiative on the flop
2. Reduce multi-way to heads-up: a raise folds out other players, making 1-on-1 play more likely

Standard open sizing in 6-max cash is usually 2.2-3bb; in tournaments, with antes, it's typically 2-2.2bb. Too small (min-raise) lets too many players in and gives insufficient fold equity; too large wastes chips and leaks range info.

The open range is determined by position — earlier positions are tighter, later positions are wider. See starting hand classification for specifics.

Common Use Cases

• No one has entered the pot: from UTG to SB, every seat has its default open range
• Facing a limper ahead: use isolation raise instead of a standard open, with larger sizing
• Short-stack open: at shallow stacks (< 30bb), reduce open size to 2-2.2bb to preserve fold equity