BB 3-Bet vs SB 4-Bet
SB 4-bet to 27 bb. Jam or call with the top of your 3-bet range; fold the bluffs.
Hands at a glance
All-in (18% of hands)
Always: AA, AKs, KK. Sometimes: A5s (30%), A4s (20%), AKo (70%), QQ (50%).
Call (13% of hands)
Sometimes: AQs (80%), AJs (30%), AKo (30%), KQs (40%), QQ (50%), JJ (80%), TT (50%), 99 (20%).
Each square is a starting hand: pairs on the diagonal, suited hands above it, offsuit below. A square split in two colors is a mix: play it each way that often.
How to play it
You 3-bet a Small Blind open from the Big Blind, and the Small Blind 4-bets. Your 3-betting range here is 12% of all starting hands (the colored squares). Go all-in with 18% of it, call 13% and fold the other 69%.
A Small Blind opens a wide range, so your 3-bet range here is wider and holds bluffs: suited aces and other hands that block the 4-bettor's strongest holdings. Those bluffs fold to the 4-bet, which is why so much of the range folds.
Related charts: BB vs SB Open, SB Open vs BB 3-Bet, SB Open Range.