If you consider the blinds as the first ‘forced’ bet, the next bet is just that - an open or bet. Raising that initial open is called a three-bet and a big bad re-raise there is called a four-bet. This article is concerned with the small four-bet, which is typically around 20-35% of your stack size, rather than the four-bet shove.
Four-bets are used in today’s hold’em cash games in a variety of ways, both for value and as a bluff. You can use them to build pots, limit fields, combat players abusing light three-bets in position and bluff players who view four-bets as incredibly strong (i.e. Aces or Kings). Because three-betting has become so prevalent in six-max hold’em, four-betting is one way of combating pre-flop aggression with a ‘fight fire with fire’ mentality. Of course there are often other options, but if you want to play optimally pre-flop, knowing when to drop the four-bet hammer will make your life far easier at tough tables.
Making money from poker is about exploitation. If you knew your opponent never varied his play and had a 100% reliable hand range for any action, then over time you would begin to build up a pretty accurate picture of what he had at any moment. After a decent sample size you would be able to map his betting perfectly and exploit him easily.
Similarly, if you only ever four-bet with A-A and K-K, your shrewd, regular opponents would be able to play you perfectly, three-betting you liberally with little risk. When you do four-bet, they can exploit you by folding and not giving your monster hand any action. For this reason we need a wider range with which to four-bet. In most medium stakes games stacking off with Q-Q+ and A-K is a given. As the table makeup gets looser and more aggressive, and if you have decided to play an aggressive game to combat three-betting, you can add J-J, T-T and A-Q. At higher stakes and on incredibly aggressive tables your range can be wider still.
Cashing in on four-bets
One key benefit of four-betting is that it allows you to generate a very aggressive image. It allows you get a decent amount of money in pre-flop with your strong holdings and get maximum value from your premium hands pre-flop. After all, if your opponent knows you play A-Q suited the same way as A-A, he can have a hard time adjusting to your bets.
Other benefits of four-betting are that it protects your late position opens and isolates against aggressive players on the button (who will three-bet you liberally if you do not adjust). A four-bet can also help to build a big pot when you are very deep and need to ensure you get fully paid, or help to negate a positional disadvantage by bloating the pot pre-flop.
The drawbacks of four-betting are that you can deviate from the most profitable line with too much aggression. For example, say an unknown loose-aggressive villain is three-betting a huge amount from any position early in a session, with hands that include all Broadway combinations and most Aces. You open the button with A-Q suited when you both have around 150 big blinds, he then three-bets from 3BB to 8BB. In this type of spot, calling is probably better than four-betting. By four-betting you open yourself up to a shove, which can be fine sometimes but without a good read on a player is a little spewy when you're that deep-stacked. Calling is better here as you can use your position, giving you more flexibility and a greater edge in the situation. By not four-betting you keep dominated holdings (such as A-x and K-Q) in the hand, which is great when you both flop something.
Read Part 2...