Sizing your 3-bets based on hand, opponent, and stack depth

by mersenneary

Throughout this series of articles, a common theme has been to exploit your opponent's tendencies and the characteristics of your hand and the situation, and not excessively worry about balance or playing an unexploitable strategy. If you're playing unexploitably, you're not exploiting your opponent. That axiom holds true when sizing 3-bets, as well. To maximize expectation, it is important to vary your 3-bet sizing based on the situation.

1. The specific hand you have matters.

How well does your hand play postflop against marginal middling hands like J8o, Q9o, and 75s? Hands like AK and ATs play poorly against these type of holdings out of position – the ace especially is a very overt part of your 3betting range and not a big portion of your opponent's flat-a-3bet range, so middling hands manage to play pretty well against your holding. Hands like KQ, KJ, and premium pairs play much better with smaller 3-bets – you'll get a lot of credit on ace high flops, dominate a lot of your opponent's calling range, and just generally make it so that your opponent can less profitably call in position.

For fanatics of unexploitability, I still question the approach, but it's important to notice that just because we're taking advantage of the qualities of our hand, it doesn't mean that our ranges are unbalanced relative to preflop strength. We can make bigger 3-bets with big aces, 88-TT, and some bluff hands, which means that we have plenty of hands that are willing to get it in. Similarly, with our smaller 3bet sizing, we have some hands that aren't willing to get it in, but also premium pairs along with giving our opponent a worse risk/reward price on a 4-bet jam. You can argue that we become unbalanced on certain flops, but for the most part, there will be strong and weak holdings in both ranges, while still taking advantage of the properties of our hand.

2. Your opponent's tendencies matter.

If your opponent is calling a lot of 3-bets, experiment in making your sizings bigger, and see what happens. Even if you make it bigger than pot with AK, and your opponent is now calling in position with insufficient expectation with hands like J5s, it's often worth it to see if they'll call bigger sizings as well, and do even better than profitable (which again goes back to our big theme – don't just be profitable, be the most profitable). If your opponent is very tight against aggression, smaller 3-bet sizings often work better.

That is fairly basic, but when you start to get a little deeper into the specifics, it becomes clear that there's a lot more to it. If your opponent opens wide but rarely 4-bet bluffs (a common default tendency of many regular players), your opponent's range contains a ton of stuff that is folding against a 3-bet. Against a 100% minraising range to t60, and assuming a 3-bet to t150 will fold out 32o-A2o, 43o-A3o, 54o-K4o, 65o-K5o, 76o-Q6o, 32s-K2s, 43s-K3s, 84s-Q4s, and T5s-J5s, this smallish 3-bet with any two cards is already close to preferable to folding, even if we were to check/fold every single time postflop! Since clearly we do much better than this after the flop, it shows not just the value of 3-betting wide against a player with these tendencies, but also of making it on the smaller side, especially with bluff hands.

There are a lot of other tendencies to think about, so this is just to get you started. How often your opponent will 4-bet is often very important in determining 3-bet sizing, which leads well into the third part of this article.

3. Effective stack size matters.

The two important aspects of stack size are how often your opponent will 4-bet, and how well your hand will play postflop if you are flat called. At shorter stacks (less than 25bb deep), hands like big aces tend to just be correct to jam over a minraise, rather than make a non all-in 3-bet. This changes only when you learn your opponent is willing to 4bet wide, particularly with weak aces and suite connectors upon suspecting that your 3-betting range has enough bluffs in it. At this point, the value from making a smaller 3-bet with AK goes way up, as those A3o type hands may fold to a jam but ship it in over a 3bet. Before that, it's generally a mistake to make non all-in 3bets less than 25bb deep with AK, and particularly a mistake when the sizing is small, allowing tons of middling hands to correctly come into the pot in position against your holding.

If you need to have a balanced 3-betting range against an opponent with bluffs in it when less than 25bb deep, it is generally best either to leave yourself with a potsized bet to go all-in on the flop, or a ratio that allows you to c-bet/fold on the flop if necessary. At deeper stacks, your 3-bet size mostly determines your opponent's 4bet jamming options – whether they can 4bet/fold, and how comfortable they can 4bet jam all-in. Again, this is why a size of 150 can work really well over a t60 open against a wide button opener – it can be really awkward both for your opponent to jam for 1350 more, or to make a non-allin 4bet with bluff hands.