Correctly Applying “Shove or Fold” Small Blind Endgame Strategy
At the end of a HUSNG, your options from the small blind will often quickly come down to two potential decisions: Commit your stack, or fold and wait for another hand. Most players understand the basic concept that when the blinds get high, it is necessary to go all-in preflop with much weaker holdings than you otherwise would. However, people often get confused by how to correctly apply “shove or fold”, when it is true that limping and minraise/folding are better options, and how to adjust your jamming ranges versus different opponent types.
When to play Shove or Fold
When to start shoving or folding exclusively will depend on effective stack sizes and the characteristics of your opponent. There is no magic number of big blinds where it becomes correct to stop limping or minraise/folding, but one good rule of thumb is that once you get deeper than 8bb, the small blind is actually at a disadvantage by only employing all-ins and folds as options. Thus, I strongly recommend searching for other options to maximally exploit your opponent at deeper stack depths. Common adjustments include limping or minraise/folding against opponents who fail to attack these plays preflop or postflop, and minraising (or limping) to induce against opponents who attack these plays too much.
Shove or fold below 8bb
Below 8bb deep, the only situations not to employ a shove-or-fold strategy are when you are playing against opponent types that react extremely poorly versus limps or minraises (generally, this will mean they are playing far too tight). Other than that, shove-or-fold is a very strong strategy. 6bb deep, your opponent is forced to put in 17% of his stack preflop before looking at his cards, while you are only forced to put in 8% of your effective stack in the small blind. That's a large advantage and can be exploited simply by choosing which hands you want to use to force your opponent to go all-in or fold when it's his action.
In general, it is correct to go all-in with a very wide range of hands less than 8bb deep. The NASH chart can help with this decision – 6bb deep, for example, it suggests that the small blind should go all-in with just shy of 70% of hands when playing against an expert opponent. The NASH chart is a good baseline of whether marginal hands are best to go all-in with at this stack depth, but in order to make the most money, you should alter your shoving range based on your opponent type. For example, NASH suggests that when two expert opponents are playing each other, the big blind will call an all-in with 98o at that 6bb stack depth. However, we have all played against opponents who we know are so tight that they would never even dream of committing all the chips with just nine high. Thus, it can be correct to shove up to any two cards at this stack depth against very tight opponents.
Against opponents who are very loose and just want to gamble when blinds get high, it is important to adjust your jamming range accordingly as well. NASH recommends jamming a hand like 86o up to 7bb deep, but part of the calculation comes from expecting hands like 87, 97, 98, T8, T7, J7, J6, and 87s all to fold to an all-in that deep. If you believe your opponent is likely calling all of those hands, don’t feel compelled to blindly follow NASH, as a slightly tighter jamming range will do better against this opponent type. Don't overdo it, though – remember that weak high card hands, like Q4o (which NASH recommends jamming at 7.9bb), become even stronger if your opponent is calling with a lot of worse trash. The main hands that are devalued are low connector cards that rely mainly on fold equity to be +EV all-ins.
Shove or fold above 8bb
The biggest, most prevalent misconception about shove-or-fold from the small blind is that the NASH chart always guarantees you won’t have negative expectation. People are fooled by the word “unexploitable”, which means something different in game theory than “guaranteed not to lose money”. If you are one of many who has not heard this before, take a step back and think about it: Surely, there is some stack depth where going all-in or folding with some range is not guaranteed to make you money. What would you think of an opponent who did nothing but either go all-in or fold 50bb? Do you think you’d have an edge? As it turns out, the big blind has the edge all the way down to around 8bb if the small blind sticks to an exclusive shove-or-fold strategy. Therefore, above this stack depth, it is important to know how to open up your playbook. Use the minraise to induce and to attempt to get folds more cheaply. Use the limp against opponents who are either too aggressive against limps or not aggressive enough (very often, it will be the latter). While the true game theory optimal strategy of HUSNGs is difficult to solve for, most people assume that such a solution, after allowing the small blind to limp or minraise, would show that the small blind has the edge again.
Still, there are hands that are still easily best to go all-in with above 8bb. Small pairs and weak Ax, for example, often play extremely poorly by minraising or limping, and all-in is generally the best option with those even up to 15bb. Don't be too scared to go all-in with these type of hands: Chubukov charts, which we’ll tear apart later in this section, show that your expectation with these types of holdings can be very good, no matter what range your opponent calls with. If your opponent rarely jams over a minraise or calls all-in shoves very loosely, it is often correct to still openjam with your strongest hands (like AK), as well.
One common strategy adjustment away from shove-or-fold above 8bb deep is to start minraising a balanced range. Combine junk hands you'll fold against an all-in and with dominating hands that crush a wide 3-bet shoving range. For example, a hand like KJ has very strong equity against a lot of 3-bet shoving hands, like J9s. By minraising, you can do much better inducing worse hands to get it all-in than you can by simply jamming yourself. However, as alluded to, a hand like A2o might do much worse with this strategy – you'd actually rather your opponent with J9s fold to a shove than go all-in against you 10bb, because it has over 47% equity against you, and it's a disaster when that hand chooses to just call a minraise because of how well it will play postflop against your Ace-rag.
Therefore, above 8bb, it's generally best to employ a mixed strategy that exploits your opponent's tendencies and makes better use of the properties of different hands in your range.
Conclusion
In HUSNGs, the endgame can be a frustrating process that feels like pure gambling. However, when done correctly, there are a myriad of different strategy adjustments that help you maximize your expectation, and crush people who think the endgame is all about flipping and following charts. Learning when and how to employ shove-or-fold will make you more confident you have edge, even when stacks get short.
