Some thoughts on 3-betting.

I post some thoughts on raising preflop and 3betting, correct me if I am wrong in some point.
Some points are quite evident, but I state them nevertheless to use later for deriving a usefull analogy.
One of the conclusions that I came to and that I am going to try for a big enough sample is the following:
‘In standard conditions (100BB stacks, somewhat competent opponents) 3bet preflop is best to do OOP, in position calling the raise with the whole range is close in EV to 3bet or may have a higher EV’.


1. Preflop raise.
What are the reasons for the preflop raise?

A. Putting pressure on blinds (limpers). We have a better hand than a random one and we want to win the blinds right now.
B. Playing bigger pot in position.
C. Isolating a weak player (limper in most cases).

What are the restrictions on the amount of the raise?

It should be big enough to put pressure on blinds, 2BB or more, IMO 2BB is a bit too low, but starting from 2,5BB it should do the job fine. On the other if our preflop raise too big 7BB or more we become exploitable by the players who are yet to act, if we raise to 7BB+ with a small range we are not going to get any action, while if we raise with a wide range they can reraise with a smaller range and make us fold after. The EV that we gain from putting pressure on blinds is not compensated by the EV that we lose due to the possible reraise.

Factoring stack sizes.

Everyone knows, that raising with a wide range against shortstacks is not a very good idea. Against big stacks we can get away with it, because we can use the position to our advantage and put some pressure postflop. While against shortstacks, the value of position diminishes as we will be AI on flop.

2. 3bet preflop.
After considering the reasons for preflop raise we can take some analogies to 3bet war and decide which factors are important when deciding to 3bet.

What are the reasons for 3bet?
A. Putting pressure to the preflop raiser. Is it a valid reason? We annonce that we have a better hand, but at the same time we narrow our hand range and we also narrow our calling range, as we 3bet the best hands. Splitting the percentages doesn’t help much, as it has the same effect on our range, with a bit more uncertainties. I would say that it’s not evident that EV that we gain by making preflop raiser fold compensates EV that we loose by giving away information about our range.

B. Playing a bigger pot. If we make a bigger pot preflop it makes the positional advantage less valid. Looking at the stack size relatively to the pot we play smaller stacks, and instead of 3 betting rounds (flop, turn, river) we will have only 2, so the value of position decreases. So we can make a conclusion that 3betting OOP is better than 3betting in position. If we change the stack sizes, this conclusion could become wrong. If we are somewhat deep we could choose to 3bet in position quite liberally to be able to play for stacks with normal betting (2/3 pot) on flop-turn-river. And vice versa OOP we could choose to just call instead of 3bet, because of deep stacks.

C. Isolating a weak player. Not very valid reason IMO, I’d rather play deeper with a weak player, so 3betting and playing with shallow stack is not a very good idea. May be minraising could do the job here.

What should be 3bet amount?

That’s somewhat harder to answer as it will depend a lot on the ranges of our opponent and out 3bet range.

In position I can see reasons for minraising as a valid 3-bet amount, our range should be just wide enough for this. Moreover of we minraise-3bet we will be able to use our positional advantage on 3 streets, but still we would be effectively playing with smaller stacks and out positional advantage would be less pronounced than in a single raised pot.

OOP we want to 3bet at least a pot sized (x3 preflop raise amount or even bigger) this way we negate our positional disadvantage (100BB stacks) and put some pressure on preflop raiser trying to win the pot preflop.


Summary:
3bet preflop in position seems to be overvalued, EV that we gain by building bigger pot preflop with better hands is somewhat compensated by the EV loss due to narrowing of our calling range. The most important, IMO, is the loss of value of our position, i.e. effective stacks are smaller and we don’t use our positional advantage on 3streets. It seems to me that calling raises with our whole range in position could be better than reraising.

I hope it makes sense, but if you see some holes don’t hesitate to object. I am still a bit unsure about this conclusion, as it doesn’t follow the mainstream 3bet practice.