Stack-to-Pot Ratios
Introduction
I could make this COTW real short and say 'if you want to know about SPR, read Professional No Limit Hold 'Em by Matt Flynn, Sunny Mehta and Ed Miller.' Since I won't do that, you'll have to bare with me. I've heard that SPR is a controversial topic in NLHE but I'm not sure why, PNLHE maybe overrated it's status a little, but SPR is an enormously helpful tool that you can use to improve your game no end.
What is SPR?
Stack-to-pot-ratios are simple. You divide the amount of the smallest stack by the final preflop pot.
For example:
We have a stack of $100, our opponent has $200 and the pot is $10 on the flop, we divide the smallest stack, our $100 stack by the final preflop pot, $10, 100/10 = 10, so the SPR is 10
We have a stack of $10 ,our opponent has a stack size of $15, and the pot size is $0.50, 10/0.5 = 20, SPR is 20
When there are more than one opponent in the hand we can calculate the SPR with all the opponents. For example we have a $300,000 stack and durrrr has a $200,000 stack but Ivey has a $500,000 stack and the final preflop pot is $10,000. That means that we have a SPR of 20 with durrrr (200,000/10,000) and a SPR of 30 with Ivey (300,000/10,000).
I hope this makes sense, it's really simple mathematics, I hope I am not making it complicated.
Why use SPR?
SPR simply puts a numerical value on the relationship between the smallest stack in the hand and the pot size. Instead of saying 'the pot was big', say 'the SPR was small'
We use SPR to help make better commitment plans, manipulate the pot preflop and to make better decisions post-flop. It isn't the be-all-and-end-all of poker as PNLHE said it was, but taking it into account is vital in my opinion.
Using SPR at uNL
Here is an example of a hand in which we don't use SPR
Hand A:
Full Tilt Poker $50.00 No Limit Hold'em - 9 players
MP1: $44.00
MP2: $14.40
Hero (CO): $50.00
BTN: $33.90
SB: $44.55
BB: $54.15
UTG: $32.00 65/19 fish
UTG+1: $40.20
UTG+2: $50.25
Pre Flop: ($0.75) Hero is CO with K
K
UTG calls $0.50 4 folds,
Hero raises to $1.50, 3 folds, UTG calls $1
make a standard raise to 3x for value, fish comes along, good.
Flop: ($2.25) 2
J
7
(2 players)
UTG checks,
Hero bets $2, UTG calls $2
Make a reasonably sized cbet on a good flop and he calls, that's also pretty sweet for me.
Turn: ($5.25) 6
(2 players)
UTG checks,
Hero bets $4.00, UTG raises to $10,
omgwtfbbq what do i do is he bluffing head asplode??
Hero made several mistakes in this hand, most of them can be avoided if he considered and used SPR effectively.
Hand B:
Full Tilt Poker $50.00 No Limit Hold'em - 9 players
MP1: $44.00
MP2: $14.40
Hero (CO): $50.00
BTN: $33.90
SB: $44.55
BB: $54.15
UTG: $32.00 65/19 fish
UTG+1: $40.20
UTG+2: $50.25
Pre Flop: ($0.75) Hero is CO with K
K
UTG calls $0.50 4 folds,
Hero raises to $2.50, 3 folds, UTG calls $2
I usually make it 3x the blinds, but if I did that that would give me an SPR of around 16 which isn't great for my hand, I'll go for a 5x raise that will give me a more favorable SPR of around 8
Flop: ($4.25) 2
J
7
(2 players)
UTG checks,
Hero bets $3.50, UTG calls $3.50
Make a reasonably sized cbet on a good flop and he calls, I think I am ahead here and given he is a big fish I think I am committed to my hand given the SPR is 8.
Turn: ($11.25) 6
(2 players)
UTG checks,
Hero bets $9.00, UTG raises to $26 and is all in,
Well I said I was committed on the flop and the 6 is unlikely to have improved his hand, I'm going to go ahead and stick to my plan and commit my chips against this aggrodonk
Hero calls $17
The biggest mistake that hero in hand A made was not that he raised to 3x after the limper but it was not making a commitment plan on any street. If he had made a plan like the hero in hand B, he would not have been put in such an awkward spot on the turn, even though the only action Hero B did differently is raise more preflop. SPR didn't tell hero in hand B how to play the hand, but it helped him create a plan and then manipulate the pot size in order to carry out the plan.
Maximum SPRs
Maximum SPRs are estimates on the largest SPR you could expect to profit when you get the money all in. We estimate maximum SPRs based on the particular hand and the particular opponent.
Pre Flop: ($0.75) Hero is CO with A
A
5 folds, Hero raises to $1.50, 2 folds, BB calls $1.00
Here is a good spot to estimate a maximum SPR. if BB was really tight that he will rarely stack off without 2 pair+, then you can say that you'll only get it all in profitably if the SPR was less than 4. That means that if the SPR was 4 or less you can commit versus this particular opponent and expect to profit. However, you estimate that if the SPR was over 4 then committing all your chips versus this opponent would have a negative expectation.
If BB was a loose spewy aggrodonk, you could say that you'll commit if the SPR was 10 or under.
Target SPRs
We can estimate the maximum SPR as the highest SPR that you can get the money all in and expect to have a positive expectation. However that doesn't mean that the maximum SPR is the optimal SPR.
PNLHE defines target SPRs as;
Quote:
your ideal stack-to-pot ratio with a particular hand versus a particular opponent. It is the SPR that is going to win you the most money when you get all in.
So how do you estimate your target SPR? Well, it depends on two major factors:
1. Your hand
This is the most important, obviously. If you've played any significant amount of poker you should know what starting hands make what type of hands by the river. AK, AQ and other big aces, broadways, and JJ+ make top pair hands and overpairs. Small pocket pairs make underpairs and sets and suited connectors make flushes, straights and big draws.
Top pair hands and overpairs are triskaidekaphobic. That means that they fear the number 13. While low SPRs like 4 or 6 are easy because you can bet/bet/commit and large SPRS like 21 aren't bad because you aren't usually stacking off anyway, 13 is a uncertain middle ground where people have just enough implied odds to set mine and draw out on you as well as having enough to bluff you off your hand. Good target SPRs with TP/OP hands are either much lower than 13 or much higher. Drawing hands like small pocket pairs and suited connectors love the number 13 for the same reason as TP/OPs hate it.
2. Your opponent
A good estimation of your target SPR has to take into account the stack off ranges and tendencies of your opponent.
A set mining nit won't commit his chips without a set or a very low SPR and will fold otherwise. You want to make as much money preflop versus this guy because he is going to play reasonably perfectly versus you postflop and with lower SPRs he is more likely to spaz out or feel committed with his pocket pair. So a good target SPR versus him might be 4.
Against a solid, aggressive TAG, you might raise that a bit. His calling range is going to be wider than just pocket pairs and will seek to bluff you every once in a while. He can also be encouraged to stack off if he hits TPTK or something of the sort, however he is still solid and isn't going to commit a lot of chips without a good hand. Against him, you can set a target SPR of 6-7.
Against a maniac fish you can set your target SPRs as high as 10-11 because he is going to do stupid stuff with stupid hands and the higher the SPR the more money you can win off him.
I have only given a basic guide, these target SPRs change because of specific reads and tendencies that every player has (remember no two players are the same). I could go through all different hands and players but I feel I don't have to, use your brain and come up with your own target SPRs for common situations that you find yourself in.
Manipulating the pot to achieve your target SPR
Once you have set a target SPR it is time to achieve that target (we set targets for a reason). Managing the preflop pot is very important because 1bb difference on the flop can mean 30bb difference by the river, and it all matters.
Raise Sizes
Raising to 3/4bb+1 per limper in all positions is the overwhelming trend in online poker. You raise the same all the time because otherwise people can read into your raise size. While this has it's merits, and it's something I do when I play, my one PSA is, STOP, THINK AND ADJUST! Your standard might be 3bb plus one bb for every limper, however doing this automatically is costing you money. Think about your target SPR and then think 'is raising to 3x going to achieve this?' Maybe you are deep with a whale and raising more isn't going to lose you value, or maybe there is a shortstack in the blinds and minraising from the button is more profitable, who knows but adjusting your preflop raise sizing every so often in order to achieve a more favorable SPR will really improve your game.
To 3bet or not to 3bet
Deciding whether to 3bet can be a difficult thing to do. Remember people have a tendency to call 3bets especially in position. So before you 3bet you should think 'if I am called I will be in a pot with a low SPR' and then think do I want to be in this pot with my hand/position against the opponent and his calling range? I see this a lot people 3bet KJo or something in the SB and then they get called and then they're like 'oh **** what do I do, I am not doing well against his range but the SPR is 5 surely I have to commit with my pair of jacks'. Well it's too late for thinking about that buddy, you should have planned it out before hand, considered all the possibilities and then made your decision. Low SPRs usually make decisions easier but they can make decisions harder when you've got a marginal hand against the opponents range and you are OOP.
Sometimes, flat-calling when you would normally 3bet can be the correct decision if you are deep.
MP1: $44.00
MP2: $14.40
CO: $61.65
BTN: $33.90
SB: $44.55
Hero (BB): $130.00
UTG: $54.15
UTG+1: $120.20 11/9 with 81% f3b
UTG+2: $50.25
Pre Flop: ($0.75) Hero is BB with A
A
1 fold,
UTG+1 raises to $1.50,
6 folds,
Hero calls $1.00
Here although we have AA and we want to get the most value out of the hand, I think flat calling here is a good play. If we 3bet to $5.50 and he calls we are setting up a pot with an SPR of 11 which is really close to 13 and 13 is bad for our hand especially against a tight player. If we just call the SPR is huge at 36 which is better for our hand as it removes the fear of getting stacked by a better hand as we are not going to stack off without a set anyway. Here by 3betting we allow him decent odds to call with smaller pocket pairs and we are going to be OOP with a bad SPR against a player who is going to play reasonably perfectly against an overpair, not a great situation in my opinion. He isn't going to stack off preflop either unless he has the other two aces.
Remember in poker there are three advantages you can have over your opponents
-Skill advantage
-Positional advantage
-Card advantage
In general, if you have skill and/or positional advantage over your opponent you can afford to have high SPRs because you allow yourself more room to maneuver and exploit these edges. If you don't have either but you have card advantage, try and aim for smaller SPRs as positional and skill advantages are less important the smaller the SPR. If you don't have any, fold.
Conclusion
if you really want to know about SPR, read Professional No Limit Hold 'Em by Matt Flynn, Sunny Mehta and Ed Miller.