SPR in Poker: What is Stack-To-Pot Ratio

SPR in poker means “stack-to-pot ratio”. Primarily, it relates the effective (smallest) stack size in play to the size of the pot, to create a sort of “risk/reward” ratio.

FORMULA: SPR = effective stack / money in pot = risk / reward

If there were $10 in the pot and the remaining effective stack size $100, then the SPR in this situation would be 10.

What does this mean? Essentially, SPR helps create an easy-to-use metric for how committed you should be to the pot for your given hand, helping simplify your post-flop decision making to some degree.

The lower the SPR, the more committed you’re going to have to be to the pot and getting your money all-in with a broader range of value hands than if the SPR was deeper.

Different SPRs are going to call for different strategies, and the purpose of this article is to help illuminate how varying SPRs should be accounted for in various situations during gameplay.

SPR Example in Action

Let’s begin with an example to illustrate the importance of SPR, suppose you have AA in early position. You raise preflop, the big blind calls, and the flop comes 875 .

Now, say the pot is $50. and your remaining stack is $150. With an SPR of 3, if you bet your Aces. and get raised, you should be able to comfortably get your stack in here, as your hand strength based on the low SPR is pretty strong here, having an over pair.

However, if the SPR is larger (say the pot is $50 and you have $1,000 in your stack), you bet your Aces and your opponent raises, then you’re put into a rather tricky situation. The big blind could have two pair, sets, straights, or some pretty good draws that could still improve.

You could lose a lot of your stack with such a relatively weak holding (based on EP vs BB hand ranges and the high SPR) if you over commit to your hand. (As such, a check-back might be more appropriate on this board against a good opponent.)

Typical Situations for Various SPR Levels

The biggest variables that are going to be determining factors of the SPR are:

1. Effective Stack Size
2. Raise Size (in big blinds)
3. Number of Players to the Flop
4. Other Factors: Straddles / Bomb Pots / Splashed Pots / Dead Money

Section 1: Online, Standard Stack Sizes

Raises in online gameplay will generally be small, between 2x and 3.5x the big blind. The number of players that see a flop in each hand is also generally much lower than found in live. This fact results in larger SPRs for both single-raised pots (SRP) and 3bet pots.

It also adds a more common possibility for there to be 4-bet or 5-bet pots with post-flop play, versus live (where it might just be a 4bet jam because of the larger open- and subsequent 3bet-sizings used)!

Section 2: Live, Standard Stack Sizes

With raise sizes being usually larger in live play (generally between 4x and 6x) and a higher potential of multiple callers seeing e a flop, these scenarios have significant potential to affect post-flop SPR drastically. The raising and number of callers leads to one of the most significant differences between online and live poker gameplay!

Factoring in a straddle will also significantly impact SPR, as it instantly halves everyone’s stack sizes, meaning SPR will be even lower than otherwise!

You’ll also notice that bomb pots (where every player puts in X amount of money, and immediately a flop is dealt), creates for action because of a subsequent low resultant SPR. The same thing is also true for splashed pots, where the casino fronts $X into the pot before any cards are even dealt!

Section 3: Tournaments

As blinds increase throughout the various levels in poker tournaments, stack sizes get much smaller (in terms of big blinds), which dramatically impacts SPR. Players usually open much smaller than a 3x or 4x open (because of the shallower stacks and to try to help keep the SPR as high as possible, making post-flop play more skill-based)

Therefore, the SPR is still generally will be much lower in tournaments than those found in cash games. As such, this is one of the reasons that variance is much higher in tournaments than in cash games: with alower SPR, players are going to be committed more easily with (relatively speaking) a wider range of “strong hands”.

Section 4: Summary Chart for Various Common SPR Situations

Implied Odds and Reverse Implied Odds

There are two basic concepts to keep in mind when dealing with SPR and choosing preflop hands accordingly (which is what we’ll touch in the next section).

Those two concepts are implied odds and reverse implied odds.

Implied odds refer to the amount of money a player can potentially win if they “hit their card(s)” and make a dominant hand, like a set, straight, or flush. The phrase that usually goes along well with implied odds is “putting in a small amount of money now to try and win a BIG amount of money later in the hand.”

Small pairs, as an example, have considerable implied odds and are going to play well in single-raised pots with a full 100bb starting stack because they’re only putting in 2bb to 4bb preflop to try to win the remaining 96bb to 98bb of their opponent’s stack post-flop(if they flop their set).

Hands with high implied odds do exceptionally well against weaker players who overvalue their top-pairs or overpairs. They all to eagerly get their money in, specifically for when the SPR is high and they *should* have more caution with such hands, as you’re learning.

Reverse implied odds refer to hands that can invest a small amount of money into the pot now and potentially lose a drastic amount later. Medium-broadway strength hands are a prime example of such hands that have lousy reverse implied odds. For example, if you’re on the button with KJ off-suitand call a raise coming from early position, you could stand to lose a big pot if you hit your top pair.

Overpairs, AK, AJ, and KQs are certainly strong possibilities of hands that are in the EP’s starting range. If you go to the flop with a high SPR in this situation, it can be easy to lose a lot of money when you pair up but get“outkicked”.Therefore, select broadway hands (seat and situation-dependent) can frequently be better as 3bets or folds when facing an open-raise.

They cut down the SPR, take the initiative, and also gain fold equity by employing a 3bet, or they fold and don’t have to worry about being affected by negative reverse implied odds from such a high SPR. 

Preflop Starting Hands Based on Flop SPR Considerations

High SPR: Suited connectors and small pairs are going to benefit well from getting involved in high SPR pots. They have excellent playability and lovely implied odds: if they make their hand, they stand to win a lot of money potentially!The same thing goes for suited AX, which can make nut flushes, and in particular, suited wheel or broadway AX hands, which can also make straights.

Low to Medium SPR: Broadway hands and some medium pocket pairs are going to do best in low to medium SPR pots. Being able to make top pair or potentially even have an overpair to a low board is going make for a strong hand at this SPR and allow you to gain value from worse hands when you bet.

Whether you’ll want to stack-off or not is situation-dependent, but as least you don’t have to worry about terriblereverse implied odds (as in the previous section)because the SPR is already in that lower to middle range. Premium hands will fare well, in general, in medium SPR pots too, but (as mentioned) there’s also some grey area for exactly how you should play particular “top pair”-strength hands (i.e.villain/board dependent).

Above all, this is the SPR stack size that hands with big implied odds (mentioned in the previous section) should avoid, as the implied odds are simply not there.

Low SPR: Premium pairs and/or hands that can make top pair with a top or strong kicker will do well in small SPR pots. Hands such as QQ+ / AK (and sometimes TT+ / AQs+ / AK vssome opponents) usually want to 3bet or 4bet to get it in, if at all possible. These holdings do better in pots where they can cut down on that post-flop SPR by re-raising pre.

If you’re just flatting a raise with AA preflop, then the SPR is staying high. You stand to lose a lot of money if someone makes a set or a flush and you end up over-committing yourself with your one-pair hand. 

The Post-Flop Strength of Hands at Different SPRs

The lower the SPR, the broader range of hands you should be willing to stack-off with, for example, top pair. The deeper and larger the SPR, the value of what becomes a “good hand” (that should be fist-bumping to stack-off/get-it-in) increases to hand values like sets, straights, and flushes.

Here’s a guideline to use regarding SPR and top pair hands, which is what James “SplitSuit” Sweeney recommends in his teachings:

• 0-3 SPR: Default stack-off with top pair +
• 3-6 SPR: Situational stack-off: dependent on board and Villain type/stats
• 6+ SPR: Not an auto-stack off with top pair (though situations versus fish or calling stations might arise where this is going to be the case).

To look at it another way, (considering more than just top-pair hands):

• 0-3 SPR: Stack-off with top pair +
• ~5 SPR: Stack-off with two pair +
• ~10 SPR: Stack-off with three-of-a-kind+
• 17+ SPR: Stack-off with strong straights/flushes+

If you end up bluffing with draws, the strength of your draw and the SPR should be factored into how you’re playing it.

EXAMPLES for DRAWS 

• With an SPR of 2 or 2.5, if you have any flush draw, check-jamming is likely a profitable option. You gain fold equity from being the one to go all-in, have decent equity when called, and aren’t risking too much having such a low SPR already.

• Not all draws are created equally, though. If you have 75 off-suit on 89J board with a medium SPR of around 5 or 6, you shouldn’t be looking to bluff-raise/get-it-in with all your draws – such as this one! Your draw isn’t the best here (there are flush draws, and better straight draws out there). You’re risking an awful lot when you could already be in a world of hurt!

• As such, the strongest of drawing hands will be good bluffing candidates for high SPR pots.

• Good drawing hands will perform well in medium SPR pots.

Skill and SPR 

The larger the SPR is, the greater that skill comes into play in determining who will be a better and more profitable player in a poker game. One of the reasons for this is because of the complexity of different post-flop bet-sizing options, range analyses, and betting lines that players can take when stacks are deeper, and the SPR is higher. The better players who can manipulate these situations to their advantage will profit more and rise to the top.

Oppositely, the shallower the SPR, the more prone to variance players will be. This scenario is one of the reasons why tournaments are such high variance games, especially those with turbo or hyper-turbo blind structures. As stacks get shallower and the SPR subsequently lowers, the requirements for which hands you should “get it in” with widens and there isn’t as much manipulation for *post-flop* skillful gameplay as there is in high-SPR situations.

That said, the skill edge that the best tournament players have is in knowing how to effectively play all the respective SPRs well (especially pre- and post-flop for the shallower-stacked levels). They can account for the varying stack sizes between players when at the poker table, meaning there *is* still skill involved, but the results that players will experience will be much more prone to variance.

10 General Tips Regarding SPR

1. SPR Should Be Used for Preflop/Flop Play: SPR is strictly used for preflop hand selection and determining relative flopped hand strength/“commitment-to-stacking-off” level of your hand for the rest of the hand. If the SPR on the flop was 10+, then use that for the remainder of the hand and proceed accordingly. Just because the river might give you an SPR of 3 doesn’t mean you should stack off anymore with the “top pair or better” mentality. Yes, you can re-calculate the size of your stack and the pot when the turn and river come ( to determine optimal bet sizings, pot odds,value to bluff combo ratios, etc.). But don’t re-calculate the SPR on the turn or river to get a new, re-defined sense of how strong your hand is. 

2. SPR Should Help You Create a Plan for How You Want to Play Your Hand: If your hand is strong but vulnerable (like the initial example in this article of AA on 875 ) and the SPR is high, checking back this flop becomes a viable option. However, if the SPR is low(between 2-3), you should be comfortable getting your money in. You can then just plan out exactly how you might want to do that (i.e. check-jam flop OR delayed cbet and jam river AND/OR use different bet sizes across multiple streets to manipulate the pot size and subsequent pot odds, etc.).

3. Study How Villain’s Range Might Hit Different Flops: When using SPR to help you create a plan for the hand,it’s essential to not just think of your SPR hand-strength, but also how the flop affects Villain’s range (compared to yours). Using programs like Flopzillacan help you visualise a breakdown of how Villain’s range connects with various boards (one pair, twopair, sets, etc.), helping influence which line of betting and bet sizing you might prefer to make for the hand.

4. Use SPR for Initial Hand Selection: If a guy is UTG with 30bb in your online cash game and open-raises, if you’re on the button with suited connectors, just pitch them into the muck. If you call (assuming it’s a min-raise), SPR would be 28/5 = 5.6 going to the flop. And as you’ve learned in this article, this is not an ideal SPR for these speculative, implied-odds hands, where you generally want a high SPR (i.e. 10+).Regarding preflop hand selection, if you’re super deepstack with a massive SPR, do be careful with the reverse implied odds hands (like weaker broadways) that could get you into trouble. 3betting or fold might be more preferable to calling with these.

5. SPR and Post-flop Hand Values: When the flop comes, makeit a habit of determining the SPR automatically so that you can know how to proceed and how “married” to your hand you should be.

6. Consider How Your Bet Sizing Affects SPR (and Continuing Ranges): Your bet-sizing choices preflop will not only play a large part in determining flop SPRbut also likely affect the continuing ranges from your opponents. And while SPR can help you gauge your hand strength for post-flop, it’s essential to also think about how it might fair up against villain’s continuing range. Starting with 100bb stacks, if you 3bet LARGE (say 2.2bb to 12bb) with ATo in a SB vsBTN situation, Villain calls, and you get an Ace-high flop, yes, you cut down on the SPR to be in that “grey zone” areaof SPR of 4.
   
   But raising so large also caused you to likely drastically narrow down Villain’s continuing range, (i.e. to very well possibly include *only* better AX hands than you, and a couple of medium pairs that you’re way ahead of). This situation could mean that you’re either way-ahead or way-behind.Would I fist-pumping to get it in here even with a SPR of 4? No. But, I probably could re-evaluate my original 3bet sizing and range – either narrowing the range to accommodate the larger sizing or bringing down the size to accommodate the larger range.

7. Stacking Off Against Fish: Remember in that grey zone are of 3-6 SPR, consider your opponent’s tendencies. Against fish and whales, you can much more liberally barrel off with top pairs and be happy to get it in. They’ll usually call of much weaker than regs would in this SPR range, especially towards the 5-6 SPR part of that grey zone.

8. You Can Be Committed, But Don’t Have To Stack Off Right Away: Just because you’re committed to your hand (i.e.

9. Draws and SPR: Always be aware of the SPR when playing your draws, primarily if you might aim to play them aggressively. You never want to bet or raise with a good-equity draw only to get your opponent to come over the top and go all-in, forcing you to have to fold, as you wouldn’t have the right pot odds. If you can, manipulate the SPR in a way so that if you wanted to, *you* could be the one going all-in with your draw (gaining fold equity, too), if you were looking to commit with it. Additionally, be aware of which specific draws you choose to play aggressively, based on the SPR.

10. SPR of Different Opponents: If you see a flop multiway, you should also give small consideration to how the effective SPR might be different between different opponents. Imagine you have AA 3-handed. One shorter-stacked opponent has an SPR of 3; another, deeper-stacked opponent has an SPR of 15. Realise that against only one of those opponents should you be happy to get it in immediately. If the shortstack folds on the flop, then it’s back to treating the hand like one which has an SPR of 15 for the remainder of it.

Summary

SPR will help give you a baseline as to how committed you should be to put the rest of your stack into the middle willingly. The smaller the SPR, the wider the stack-off hand values can be. The higher the SPR, more skill in post-flop gameplay will become prevalent, and stronger valued/higher implied odds hands will end up performing better.

Get into the habit of always keeping a tally on what the SPR might be in a given spot. That way, you can construct your ranges and betting lines appropriately and profit the most at the tables.