Check Raising in Poker
The check-raise is an essential tool for all poker players to have in their arsenal, particularly in aggressive shorthanded online cash games. In its basic form the check-raise is designed to show weakness with a check, enticing a bet from your opponent, which you then raise hoping to build a pot or have him fold, depending on your objective.
The Most Common Spot for a Check-Raise
Online poker has become very aggressive, and by far the most common scenario for a check-raise in a shorthanded cash game is when a player raises in late position to steal the blinds and one of the blinds calls the raise then puts in a check-raise on the flop. This move works extremely well as a bluff simply because the pre-flop raiser’s range will be very wide as he was in late position, and thus his hand strength after the flop will be on average quite weak, but he will continuation bet very often. Of course we can’t get away with check-raising every time a player continuation bets in late position or we will be quickly exploited.
Let’s look at an example:
Say you are in the big blind facing a raise from an aggressive player on the button and you call and the flop comes down 4s5h8s. On this board you would be check-raising for value with all sets and 67-suited which will sometimes be in your range for defending the big blind. This represents 13 hand combinations.
Game theory suggests that to remain balanced you need to be check-raising with a bluff:value ratio of about 2:1, meaning you should be check-raise bluffing with 26 of your pre-flop combinations on a board like this. When you do decide to bluff, you should be choosing hands like 9hTh and Ac6c which have good equity against your opponent’s continuing range.
Math of the Check-Raise
Staying with the button vs. blind example, let’s take a look at the math involved in check raising in poker, and bluffing in particular. Let’s assume your opponent raises to 3 big blinds and you call from the big blind, then he bet’s 5 big blinds on the flop. For simplicity we’ll assume the small blind is taken as rake. The pot is now 11 big blinds. A typical check-raise of his bet might be to about 16 big blinds, which means you’re risking 16 to win 11, and so you need your bluff to work [16/(16+11)] = 60% of the time.
In today’s games people are opening 50% of hands on the button and continuation betting 80% of the time, giving them [1326 x 0.4] = 530 hand combinations. When they can only realistically continue with sets, straights and some over-pairs and flush draws, it becomes obvious just how profitable check-raise bluffing can be, particularly if your hand has some equity against their continuing range. Of course as stated earlier, this is only the case if your opponent hasn’t adjusted to your aggressive check-raising strategy. Typically keeping your check-raise statistic in or around 10% is optimal. In the example above you can see that you should be check-raising 39 combinations. If you call pre-flop with about ~15% of hands (~180 combinations), you can see that you need to be check raising a board like this more than 20% of the time!
Dealing with Opponents who Check-raise Often
The most obvious way to deal with very aggressive opponents who are check-raising your continuation bets with a very high frequency is to check-behind on the flop more often. Against some opponents it is profitable to bet a hand like Ah7h on a board of 4s7sTc, because you will get value from straight draws, flush draws, pocket pairs like 55 and 66 and worse 7’s.
However if you get check-raised after betting you have to fold, and if your opponent is very aggressive, you’ll often be folding the best hand. In this scenario it’s much better to check behind and turn your hand into a bluff catcher, or to bet the turn when your opponent’s draws have much less equity and he will be less inclined to check-raise. Of course when employing a flop strategy that includes checking behind more often, you mustn’t give your opponent the green light range to bluff you on the turn and river. If you are only checking behind your marginal showdown hands and betting all of your strong hands and bluffs on the flop, you’ll be very easy to play against. You have to make sure to balance this by checking back strong hands like sets occasionally; even on boards that appear slightly draw heavy.
Check-raising as the Pre-Flop Raiser
There has been a lot of discussion and debate over the years about whether it is necessary to have a range for check-raising when you’re the pre-flop raiser. In single raised pots this situation will typically arise when you’re in early position and have been called by the cut-off or button.
The general consensus is that there is no real need to have a check-raising range here. Checking gives your opponent the opportunity to check back hands which he would’ve called a bet with that have equity against your hand. For example if your opponent knows that you are capable of check-raising as pre-flop raiser he’ll be more inclined to check back weak flush draws or second pair hands which have five outs against top pair.
You can protect your checking range simply by check calling, both with your weak bluff-catcher hands and with very strong hands. Check-raising in this spot is very difficult to balance as your opponent will usually be able to narrow your range down to either monsters or bluffs as check-raising medium strength hands here is a very advanced play and requires an aggressive dynamic and history with your opponent.
In games with big player pools it will be very difficult to get a read on how your opponents will react to a check-raise from the pre-flop raiser and so for the most part there’s no need to have it in your game.
Check-raising on Later Streets
Check-raising on later streets, where ranges are narrower and the stack-to-pot ratio is much shallower typically commits both players to the pot if there is further action. If there are 16 big blinds in the pot on the turn and there is a bet of 12, a check raise might be to perhaps 30 big blinds, meaning the raiser has put in over one third of his stack. Typically in this spot if the bettor is to continue he will be pot committed.
Check-raising as the pre-flop raiser is much more common on the turn than on the flop. The line of raising pre-flop, betting the flop and check-raising the turn used to be known as the ‘stack-a-donk’ line. Nowadays, check-raising the turn is a common tool to use against players who ‘float’ a lot (call the flop with a weak hand with the plan to take the pot down with a bet on the turn when you show weakness).
The call pre-flop, check-call flop, check-raise turn line is typically taken by transparent players on dry boards who want to get maximum value from their strong hands on dry boards. It is true of most small to mid stakes players that check-raise on the turn or river polarizes their hand range to nuts-or-air very often; though good players will be capable of check-raising turned equity such as backdoor flush- or straight-draws.
Facing a check-raise on the river puts you to a slightly different decision than on earlier streets. At 100 big blinds deep a check-raise will typically put the player all-in and give odds of close to 2.5/1 on a call. On the river however, you either have 100% equity or 0%, so your decision comes down to whether you think your opponent is bluffing 40% of the time when they make the check-raise.
Again, you can be almost certain that your opponent is only taking this line with his very strong hands and bluffs like missed draws or hands with showdown value which he has decided to turn into a bluff on the end.
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