4-Bet

Also known as: four-bet, 4bet

The fourth bet in a preflop sequence — a reraise over a 3-bet, typically with a polarized value-plus-bluff range.

A 4-bet reraises a 3-bet. Because a 3-bet already represents strength, the 4-betting range is sharply polarized: premium value that wants stacks in (QQ+/AK, sometimes JJ/AQs depending on positions and depth) plus a measured set of bluffs chosen primarily by blocker quality — Axs and Kxs hands that block the opponent's 5-bet/call value combos (AA, KK, AK).

Sizing depends on position. IP 4-bets can be small (≈2.2–2.5× the 3-bet) since you realize equity well; OOP 4-bets go larger (≈2.5–3×) or jam outright at shallower depth. The bluff-to-value mix is governed by the price you lay: if your 4-bet risks \(R\) to win pot \(P\), the bluffs need fold equity such that \(\dfrac{R}{P+R}\) is cleared by folds — typically your 4-bet range is value-heavy, around 1 bluff per 1.5–2 value combos OOP.

In MTTs, stack depth drives everything: under ~25bb the 4-bet is usually an all-in (no room to fold to a 5-bet), and ICM pressure thins the bluffing region considerably.