Ships and planes find the Bermuda Triangle with less difficulty than many players find the perfect bet size. And it's understandable. After all, there is no perfect bet size. Not strictly speaking. There’s only an ideal bet size for the situation you are in, at that precise moment. Chances are, over the course of your entire poker career, you will never, ever be in that exact situation again, even if you do find yourself in similar ones, giving you a seemingly endless number of perfect bet sizes. It’s almost enough to make disappearing in the Bermuda Triangle a welcome prospect.
But fear not. Bet sizing is not as hopeless at it seems. While there’s no one perfect bet size, there is a solid system you can use to help you find the perfect bet size in any situation - and I'm going to share it with you now.
One system, endless possibilities.
Well, not endless. Unless you plan on living forever and have a limitless supply of opponents, there will only be so many spots to play. Knowing how to take lucrative action in those spots involves knowing how to size your bet.
Fundamental Bet Size Theory
1/4, 1/2/ 2/3, 3/4, full pot. At the ends of the extremes, you have min bet and over-bet. These are your basic bet sizes.
Now we need to determine when to use which one. Before we get to this, though, I want to mention that bet sizing is part art, part science. Yes, the numbers are important, but a large part will depend on your ability to draw nuanced intel from your opponents, which is more of an art than an exact science. With this in mind, as long as you have a general handle on your opponent’s calling range, even if you’re an increment away from making the ideal bet, it is still going to be a profitable move.
So now you need a basic knowledge of calling ranges. Thankfully, there are only two kinds you need to know about: Elastic and Inelastic.
Elastic: These calling ranges are sensitive to changes in the environment. An opponent will call with different sets of hands based on your bet size.
To play profitably against an elastic range, you want to extract as much value as possible. To do this, bet small to get action from opponents with a wide calling range and bet big to get action from opponents with a narrow calling range.
Inelastic: These calling ranges are static. An opponent will call with the same hands regardless of the size of your bet.
With this sort of calling range, you want to bet big to extract value. Bet as big as you think that opponent will call -typically 75% -90%. Employ this tactic on the river whenever possible, since your opponent won't have time to out draw you. Your equity is pretty much fixed.
Bluffs can be used against inelastic calling ranges, but you are always going to want to value bet more than you bluff.
Your pay off can be calculated like so: the # of hands that call * the bet size.
Getting a feel for when to do what and how much won't come automatically, and you won't be able to do that calculation on the fly, so run through some samples in your study time and see what yields the best results. For example, decreasing your bet size by 10% could get you called by 50% more hands, so it would be worthwhile. But, in other situations, decreasing your bet size by 50% could only get you called by 10% of hands, so it's not a profitable play. Practice and be patient. This situational intuition will take time to develop.
The question you have to ask yourself is this: How much do I change my bet size so I still get called by enough hands to be worth more than if I bet smaller?
Likewise, your reading of your opponents calling ranges won't be spot on at first, but the more you practice, the better you'll get at it.
Figuring out whether or not you are up against an elastic or inelastic calling range comes down to what your range is composed of and how accurately you are reading your opponent's range.
If you are polarized to only having nuts or air, you're facing an inelastic situation and your opponent is going to fold to your value hand and call your bluff. If, however, your range consists of many different strengths of value hands - from weak to super strong as well as bluffs - then you are facing an elastic situation.
The Check-Raise Dilemma
Now, while what I am about to say isn't strictly related to finding the perfect bet size, it often affects a player's ability to work this out. I'm talking about the dreaded check-raise. Many players opt out of value betting because they are afraid of being hit with this move, but I'm here to tell you not to worry about it.
Most opponents, especially in micros, are not capable of bluffing or check-raising the river. They just don't do it. It doesn't even cross their minds as a strategic option because they don't think they have a chance.
Your goal is to simply choose bet sizes that show the highest expectation. And don't forget to factor in the mighty power of spaz equity: you know, that extra edge you get when you make a bet that pisses your opponent off and they act out of dumb spite and do something stupid.
Remember: every time an opponent makes a mistake, it's your gain! And one of the biggest mistakes is not taking the time to improve their play, which you’re doing now, so you’re already ahead of the game.