SB vs BU open

PokerStars - $0.02 NL (6 max) - Holdem - 3 players
Hand converted by PokerTracker 4

Hero (SB): 100.5 BB
BB (BB): 201 BB (VPIP: 0.00, PFR: 0.00, 3Bet Preflop: -, Hands: 1)
BTN (BTN): 104.5 BB (VPIP: 0.00, PFR: 0.00, 3Bet Preflop: -, Hands: 1)

Hero posts SB 0.5 BB, BB posts BB 1 BB

Dealt to Hero:
2s2h

BTN raises to 2.5 BB, Hero raises to 8.5 BB, fold, fold

Hero wins 6 BB

Okay, this was a fun hand. The button opened, I went for a light three bet with 22, and he folded. Actually, I thought this would make a good basic hand to do some research on. There are really only two decisions here, so it should be nice and simple.

So the first question is, what are some reasonable button open frequencies here? And my second question is, what should our strategy be from the SB vs button opens of varying frequencies? Also, what should our strategy be against an unknown button open?

I have found and reviewed a number of online discussions on this subject, doing my best to highlight interesting comments, filter out the noise, and add my perspective as well.

Discussion One

In a discussion on 2+2 a user suggests a 30% to 40% range for button opening frequency, which seems reasonable. Two users then suggest opening an 80% range, or a range of 53s+, 63o+, and 22+ which is a 90% range. That seems far too wide. The user TopPair2Pair made a pretty good point saying 

This ultimately ALWAYS depends on who you have in the blinds. NEVER open steal with identical hands all the time - it always dependent on who is in the blinds!!!!! Prime candidate are nits, mass multitablers, occasionally they are not both, sometimes even weak tight regfish depending on 3bet and bbfold %s.

Although the phrasing "never open steal with identical hands all the time" seems a bit awkward. What he probably means - or what I would say is accurate at any rate - is that you shouldn't open the same frequency regardless of who is in the blinds. Vs some players we should open more aggressively and vs others we should exercise caution. What is noteworthy in his commentary is his identification of 'mass multitablers' or specifically players who are playing too many tables and not defending their blinds enough as a result as targets for widening your opening range. This is noteworthy because it extends the analysis beyond simply what is happening at the table to what is happening at the site, or even beyond the site.

The user 'breathweapon' also had an interesting perspective.

Raising 100% of hands is harder to exploit than people realize, not in the sense that it isn't exploitable but in the sense people make terrible adjustments to your strategy which are in turn even more exploitable. Vs. guys who love to 3bet, I'll decrease my raise size and increase my stealing frequency just to watch them go crazy and then win it all back with a will timed 4bet or just call them with the nuts and watch them bluff off their stack. It's especially effective vs. the SB, who over compensates with 3bets specifically to isolate you and then you and the BB are pretty much salivating over how imbalanced his range is now.

 

 

This discussion is from 2010, so it is in the pre-solver era.

Three Betting From SB vs BU Open

In this discussion on 2+2, a consensus is quickly reached that a 15% to 17% three betting range is optimal vs BU open. However no consideration was given to BU opening standards. I will assume they were talking about standard 40-50% ranges.

Looking at GTO Wizard, they suggest a 2.5 x BU open with a 42% range. Vs this range, the SB is supposed to three bet 15% of the time. 

The bottom of your range are hands like ATo, 66, KTo, and A2s. But most of those hands are only partial or 'mixed' three bets. 66 for example is played as a three bet to 12 bb 17% of the time and folded the rest (technically there is a smidgen of call in there as well).

So there you have it, the three bet was not 'gto approved'.