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BB Defence vs Cutoff Open (6-Max)

Against a cutoff open you defend about 29% of hands from the big blind — 3-bet roughly 6% (TT+, AQs+, A5s–A4s, AQo+, KQs) and call about 24%. Much tighter than against the button, because the cutoff opens 29% instead of 51%.

Chart

AAAKsAQsAJsATsA9sA8sA7sA6sA5sA4sA3sA2s
AKoKKKQsKJsKTsK9sK8sK7sK6sK5sK4sK3sK2s
AQoKQoQQQJsQTsQ9sQ8sQ7sQ6sQ5sQ4sQ3sQ2s
AJoKJoQJoJJJTsJ9sJ8sJ7sJ6sJ5sJ4sJ3sJ2s
AToKToQToJToTTT9sT8sT7sT6sT5sT4sT3sT2s
A9oK9oQ9oJ9oT9o9998s97s96s95s94s93s92s
A8oK8oQ8oJ8oT8o98o8887s86s85s84s83s82s
A7oK7oQ7oJ7oT7o97o87o7776s75s74s73s72s
A6oK6oQ6oJ6oT6o96o86o76o6665s64s63s62s
A5oK5oQ5oJ5oT5o95o85o75o65o5554s53s52s
A4oK4oQ4oJ4oT4o94o84o74o64o54o4443s42s
A3oK3oQ3oJ3oT3o93o83o73o63o53o43o3332s
A2oK2oQ2oJ2oT2o92o82o72o62o52o42o32o22

3-betCallMixedFold

3-bet: TT+, AQs+, A5s, A4s, AQo+, KQs
5.6% of hands (74 combos)

Call: 22-99, A2s-AJs, K7s-KQs, Q8s-QJs, J8s-JTs, T8s+, 97s+, 86s+, 75s+, 65s, 54s, ATo+, A5o, KTo+, QTo+, JTo
23.5% of hands (312 combos)

The rule that generates every big-blind defending range is simple: defend against strength, not against position. The cutoff opens 29% of hands versus the button's 51%, so the average hand you face is materially stronger. Your pot odds have not changed — you still need about 22% equity — but the equity your junk hands have against a 29% range is much lower, so the defending range shrinks by about half.

The other reason to tighten: there is still a player behind you (the button) who can squeeze. When you call wide from the big blind against the cutoff, you are not just facing the cutoff — you are inviting the button into a pot where you are out of position to both of them.

The 3-betting range narrows accordingly. A5s and A4s stay in as the bluffs (same blocker logic as against the button), but the value portion tightens to TT+ and AQ. KJs and AJo, which are 3-bets against the button, become calls here — they are dominated too often by the cutoff's tighter opening range.

FAQ

How much should I defend from the big blind against a cutoff open?

About 29% in 6-max — roughly 6% as a 3-bet (TT+, AQs+, A5s–A4s, AQo+, KQs) and 24% as a call. That is roughly half as wide as your defence against a button open, because the cutoff's opening range is about half as wide.

Why do I defend less against the CO than against the BTN?

Because the cutoff opens a stronger range (29% versus the button's 51%), so your marginal hands have less equity against it — and because the button is still to act behind you and can squeeze. Both effects push the same way: tighten up.

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Related charts

BB Defence vs Button Open (6-Max)BB Defence vs UTG Open (6-Max)UTG Opening Range (6-Max)8bb Push/Fold Chart (9-Max Nash)

All preflop charts

Cash-game ranges are a curated GTO reference, drilled question-by-question in the trainer. The mixed band lists hands solvers play only part of the time.

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