IP 4-Betting in Deep-Stacked Cash Games

Here are some key takeaways we’ll explore further below:

Preflop Strategies

To explain these patterns, we must look at how both players’ preflop strategies vary with stack size. The SPR is far from the only thing that changes when we compare 100bb flop scenarios to 200bb flop scenarios.

For one thing, the SPR doesn’t change as much as you might expect because both players use different preflop raise sizes with 200bb than with 100bb. For OOP, the difference is not enormous, but whether they raise larger or smaller depends on their position—sitting as the SB or the BB.

Deeper stacks incentivize a more polar 3-betting range for OOP.

When Not To Continuation Bet

BTN’s most checked flops when 200bb deep are all medium-to-high connected flops where BB is more likely to flop straights, sets, and two pairs. This is true regardless of whether they are playing against SB or against BB.

These may not be the best spots to study, however, because BTN should not face many checks on these flops in the first place. Both SB and BB donk-bet their entire range on T98 and bet aggressively on these other flops as well.

As a rule, medium flops are worse for betting than low flops, which are worse than high flops. King-high flops are the very best, as the OOP caller has more Ace-x in their calling range than King-x.

As we have seen already, connected flops are the worst for c-betting. This is partly because OOP will flop more straights but also because connected flops are likely to contain medium cards, which are more likely to help OOP.

Of the King-high flops, the one BTN checks most often vs BB is KQ9 monotone. Checking here is not about this being a bad flop; BTN flops more than 55% of the equity and captures nearly 58% of the EV. Rather, it’s that this is an extremely static board. So, most hands do not strongly prefer betting earlier rather than later streets.

All hands mix bet and check, with even the stone bottom of BTN’s range, A♣6♣, being profitable as a bet.

In fact, many of BTN’s most-bet hands are among their weakest! This is not a time for checking and giving up when you miss. When BTN checks a weak hand, it’s with the intention of bluffing later should their opponent keep checking.

This holds true on less favorable textures as well. On J♥5♥5♦, the BTN flops less than half the equity and has a similar checking frequency but still gets profitable bluffs with their worst hands:

Even on Q95r, where BTN has less than 44% equity, they bet often, including with their worst hands:

Unlike an OOP 4-bettor, an IP 4-bettor does generally get profitable bluffs, even on bad flops. That doesn’t mean you have to bet the flop, but you should bluff at some point if your opponent keeps checking. The best hands for checking the flop are generally not your lowest equity hands but rather the middle of your range, the sort that would suffer the most from facing a check/raise.

Responding to Donk-Bets

Donk-betting is a significant part of OOP’s strategy in 4-bet pots. This is especially true when deep-stacked and playing from the BB, because of how much strength that BB calling range contains. On average, they donk about ⅓ of their range, with most of that betting occurring on their best 25% or so flops. The aforementioned medium, connected flops are strong candidates for range-betting and sometimes even open-shoving more than twice the pot!

BTN’s response to a shove on T98r is mostly intuitive, though the mixes with AKs (only when it has a backdoor flush draw) and AQo may be a bit surprising. The incentive for these calls comes largely from the fact that AJ is among BB’s most appealing shoves.

Your response to a smaller donk-bet should be quite stubborn. Across all flops, BTN has an average fold frequency of ~17% vs BB’s quarter-pot donk-bets, a frequency slightly below MDF.

Note that raising is an important part of IP’s response as well, especially on boards that favor them. High card boards get mostly small raises, while the rare 5-high and 4-high flops are good candidates for shoving. Most of these boards will give overcards and at least a backdoor wheel draw to all the Ace-x in IP’s range, which means they wouldn’t have many good candidates for folding after making a small raise.

On the much less favorable T98r flop, BTN never raises a quarter-pot bet and folds at a higher frequency than MDF, which is why BB can range-donk.

On a more neutral J55tt, donking is not a big part of BB’s strategy, but should BTN face such a bet, they raise a wide and fairly polar range. The best candidates are AA and KK, which unblock top pair, and A♥K♥, which has solid equity against top pair and can get action from dominated flush draws. At the low end, weaker overcards with a single heart are popular candidates, though even some overcards without hearts get mixed in at a lower clip.

Much of the incentive for the raising range comes from the dynamism of the board. Aces and Kings would like to raise into a Jack immediately, lest they lose action when a heart or overcard turns.

On the more static A♥Q♥9♦ board (staticness here refers more to the rank of the cards on the flop than to the number of draws, especially when the SPR is low), BB donks about half their range, but BTN never raises. Instead, they call more than MDF:

Ranges are narrow enough in a 4-bet pot that calling 84% of their range doesn’t require much stubbornness on BTN’s part. Backdoor diamonds and Jacks without a heart are pure folds. BTN simply has a pair of Queens or better so often on this flop, they don’t need to continue with much else. And when they do have those hands, there’s not much to gain from raising them.

Conclusion

Making sense of postflop play requires understanding preflop ranges and incentives. An OOP 3-bettor has different incentives than an IP 3-bettor, and different incentives depending on the stack depth as well. The BB is incentivized to 3-bet a more polar range than the SB, which influences how IP responds to the 3-bet, which in turn influences OOP’s range when they call a 4-bet and see a flop.

The higher SPR and stronger OOP range lead to more checking and larger, more polar c-betting from IP. It also leads to more donk-betting, especially from the BB.

Because IP’s 4-betting range is so clustered around Ace-x and King-x, they perform better on high card flops. This usually but not always leads to more aggression, whether facing a check or a small donk-bet, with the dynamism of the board being a major determinant of how aggressive they get.

Unlike OOP, an IP 4-bettor does generally get profitable bluffs, even on unfavorable flops. They don’t always bet their worst hands on the flop, but they do bet them eventually if their opponent keeps checking.