SB 10bb 3-Bet Jam

Overview

The SB 10bb 3-Bet Jam is a common short-stack strategy in no-limit hold'em tournaments. It occurs when the small blind (SB) has approximately 10 big blinds (bb) and faces a raise from a late-position player (usually the button or cutoff). Instead of calling or making a smaller 3-bet, the SB moves all-in. This play is aggressive and leverages fold equity, as the raiser must call off a significant portion of their stack to see a showdown.

Why 10bb?

At 10bb, the small blind is in a critical zone. Their stack is too small to make a standard 3-bet (e.g., to 2.5x the raise) and then fold to a 4-bet jam, as that would commit too much of their stack. Calling is also risky because they'll be out of position postflop and may face difficult decisions on later streets. Jamming preflop simplifies the decision: either win the pot immediately or get to showdown with a hand that has equity against the caller's range.

Effective Stack Considerations

• Less than 10bb: The 3-bet jam may be too large relative to the pot, reducing fold equity. Often, a direct open-jam or limp-jam is preferred.
• More than 10bb: Jamming may be less optimal because the raiser can call lighter, and the SB risks elimination when called. A smaller 3-bet (e.g., to 2.2x the raise) becomes viable to preserve fold equity and pot control.

Range Construction

A typical SB 10bb 3-bet jam range includes:

• Value hands: Strong aces (AT+), broadway pairs (77+), and suited broadways (KQ, AJ).
• Bluffs: Hands with decent equity but not strong enough to call, such as low suited connectors (65s, 87s) or weak aces (A2-A5). The bluff frequency should be balanced based on the opponent's raising range and fold tendencies.

ICM and Tournament Context

In tournaments, the SB 10bb 3-bet jam is heavily influenced by Independent Chip Model (ICM) considerations:

• Near the money: Jamming becomes tighter because the risk of elimination outweighs the chip gain.
• Short stack bubble: The SB should jam only premium hands, as the raiser will call wider with ICM pressure.
• Deep in the money: With high blinds and antes, the jam can be wider to accumulate chips.

Example

Blinds 500/1000, ante 100, effective stacks 10,000 (10bb). The button opens to 2,200. The small blind looks down at A♠5♠. A standard 3-bet to 5,500 would commit over half the stack, leaving a difficult turn decision. Instead, the SB jams all-in for 10,000. The button must call 7,800 to win 13,700 (10,000 + 2,200 + 1,500 antes). The button may fold weaker hands like KJo or 77, while calling with AQ+ and TT+. A5s has about 35% equity against that calling range, making the jam profitable given the fold equity.

Conclusion

The SB 10bb 3-Bet Jam is a high-variance but mathematically sound play when ranges are properly constructed. Its success depends on fold equity, opponent tendencies, and tournament dynamics.