Very weak offsuit one-gapper

Four-Three Offsuit

43o is usually a fold because its low ranks make weak pairs and its one-gap structure rarely produces a strong straight. It has no flush backdoor from 43o, and a low pair is often dominated by a higher pair.

How to play 43o by position and stack size

Recommended action	UTG8-max	UTG18-max	LJ6-max	HJ6-max	CO6-max	BTN6-max	SB6-max
100bb+	Fold	Fold	Fold	Fold	Fold	Fold	Limp
40-100bb	Fold	Fold	Fold	Fold	Fold	Fold	Limp
27-40bb	Fold	Fold	Fold	Fold	Fold	Fold	Fold
20-26bb	Fold	Fold	Fold	Fold	Fold	Fold	Fold
16-19bb	Fold	Fold	Fold	Fold	Fold	Fold	Fold
11-15bb	Fold	Fold	Fold	Fold	Fold	Fold	Fold
7-10bb	Fold	Fold	Fold	Fold	Fold	Fold	Fold
6bb-	Fold	Fold	Fold	Fold	Fold	Fold	Fold

Open when:Almost never

Its low rank and poor connectivity do not provide enough fold equity or post-flop value for a standard open.

3bet when:Never as a standard bluff

It has no high-card blocker and is dominated when called.

Call when:Only to check the big blind

A free flop can justify seeing a board, but paying a raise creates too many dominated pairs.

Jam when:Only in a rare short-stack ICM spot

The decision must come from the tournament situation, not from 43o's post-flop strength.

Fold when:Facing a raise or 3-bet

Its pair outs are weak and its straight potential is too narrow.

Strong against

No strong matchup to highlight.

Weak against

A4o
A4o shares the Four with the better kicker, so 43o can make a costly second-best pair.

Flop classes

Made seven-high straight

On 5♣ 6♦ 7♠, 43o already makes the 3-4-5-6-7 straight. Bet for value, while watching for higher straight possibilities on later streets.

Paired low

On 4♣ 8♦ 8♠, a pair of fours is vulnerable to higher pairs and better four-x hands. Check and fold to sustained pressure.

High dry

On A♠ K♦ 9♣, 43o has no pair or straight draw. Give up unless checking is free.

Strategic notes

Versus 3-bets

Fold: Fold every standard 3-bet.
Do not defend: Even with position, 43o lacks a high-card blocker and rarely flops enough equity to continue.

Post-flop playability

Check or fold: After checking the big blind, continue with a pair plus a specific draw or with a very favorable price.
Do not call with any pair: A three or four can be dominated by better kickers and higher pairs.
Fold to pressure: Without a made straight or a real straight draw, later-street aggression usually exploits 43o's reverse implied odds.