One of the more important concepts in poker is SPR. Knowing how to use SPR is a vital skill that will help you play better both preflop and postflop. SPR is a measurement of commitment, helping us visualize when we are automatically committed to a pot, never automatically committed to a pot, and when it’s a grey-zone situation. Watch this video to get an idea on how to calculate and visualize this metric. Or if you enjoy reading, the script for this video can be found below. Enjoy!
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Hello, and welcome to today’s Quick Plays video on using SPR. SPR is a powerful concept that was first introduced in the twoplustwo book “Professional No-Limit Hold’em: Volume 1” by Matt Flynn, Sunny Mehta, and Ed Miller, In this video you’ll learn what SPR is, how it’s useful, and ways to choose better lines.
SPR is an acronym for Stack to Pot Ratio. We use SPR as a preflop and flop metric for how automatically committed we are to a pot. To figure out the SPR we can use this very simple formula of:
SPR = Effective Stack Size / Pot Size
And remember that the effective stack size is the smallest of the stack sizes involved in a hand…
So in this hand we 3bet with AA, MP calls us, and go heads up. We see that MP has the smallest stack between the two of us and thus the effective stack is $55 and the current pot size is $21.5. Using our simple formula we divide $55 by $21.5 and see that our SPR is 2.6. But what does that number really mean to us?
The general idea with SPR is that as the SPR gets smaller you are more automatically committed to the pot. And on the contrary, as the SPR gets larger you are less automatically committed to the pot. A small SPR is 2 or less, a medium SPR is between 3 and 6, and any SPR larger than that is big. In small SPR pots we are automatically committed with top pairs, overpairs, big draws, etc. Being committed simply means that we push comes to shove, we’ll get our stack in the middle. Whether our opponent shoves, we bet and face a CR, or we simply bet the flop AND turn…we are happy committing our stack
Now it should go without saying that starting stack sizes will influence the SPR a ton. A player with a small stack size, say 20bb, is going to wind up in small SPR pots quite often. Say he open-raises to 3bb and gets a single caller from the button, then he sees the flop with an effective stack size of 17bb and a pot size of 7.5bb, for a 2.3 SPR pot. Whereas if they both had 100bb starting stacks then they’d have effective stacks of 97 on the flop and a pot size of 7.5 for an SPR of 13.
Another big influencer is going to be single raised versus 3, 4, and 5bet pots. The more raises that go in preflop the bigger the pot size will be on the flop and the smaller the effective stacks will be…inherently lowering the SPR. It’s very common for an SPR to be around 4.5 in a 3bet pot with starting stacks of 100 big blinds, whereas 4bet pots are much smaller.
And lastly, you need to remember that SPR is a preflop and flop metric. We don’t recalculate the SPR on the turn or river, so please don’t get confused and make that mistake. That being said, we still carry our SPR commitment ideas from preflop and the flop INTO the turn and river. So if we got to the flop with 2.6 SPR with AA on J94 we know we are committed to the pot given we have an overpair AND a small SPR pot. If we bet the flop for $15 and he calls, we keep that same committed mindset going into the turn. Meaning we will usually keep betting if he checks, and if he shoves himself we are going to call.
Even when we are automatically committed to a pot it doesn’t mean we will always win the hand. Sometimes we’ll create a small SPR with a monster hand and our opponent will call with a small pair and spike a set to beat us. Or call with a suited hand and spike a flush to beat us. The big thing to remember is that in the longrun he is making the MUCH larger mistake by getting involved in a small SPR pot with such a hand. He won’t hit strong enough, often enough, to justify his call. And while he may be rewarded once in a while, rest assured that your stack off in these small SPR pots is going to be profitable in the longrun.
Which brings us to a vital point. We want to be very selective with the hands we use to enter small SPR pots. In those small SPR pots we will be committed, or close to it, and we want to use hands that would be profitable in that environment. Be forward thinking and consider the SPR you will be getting involved in if you do decide to call that 3bet or 4bet preflop. In this example we open with 88, face a 3bet from a smaller stacked player, and if we think ahead we realize that by calling we would put ourselves in a small SPR pot. If we call the pot size would be $19.5 on the flop, the effective stack would be $31, and thus the SPR would be 1.6.
This is a very committing SPR, one that is great with hands like AA or KK, but super tough for hands like 88. Rather than call and put ourselves into what will likely be a very -EV situation, we likely should 4bet or fold…all because we thought ahead and considered the SPR before just auto-calling preflop with to our pair. With small-medium pairs we like much deeper SPR pots so there is a lot of money left to win when do flop our sets and so we aren’t committed to a pot with weak single pairs.
To make this more visual lets quickly graph 0-10 SPR and understand which hands perform best in each area. In the left area, as we get closer to 0 SPR, we want to use our strongest of hands. Hands like AA, KK, QQ, and AK are standard. Against fishy opponents we may even loosen this up to include JJ, TT, or AQ. As we begin to slide to the far right and get into the 8+ SPR zone hands like 65s and small pairs begin to play much better. These deep SPR pots offer more more postflop money to be won which can give these hands the implied odds they need. Notice that these implied odd type hands don’t perform well in very small SPR pots because there isn’t enough money left in the stacks for us to win big when we smash a flop.
In the middle is the toughest area to talk about since it’s kind of a grey zone. And with any grey zone in poker there are a lot of “it depends” kinds of situations. The way that I visualize the grey zone is that I want to use the strong hands more often, very away from the implied odd type hands, and tighten/loosen my standards based upon villain. If I’m in a 4 SPR pot with QQ I’m likely to always stack off postflop with an overpair against a fish. But if villain were a nit I don’t think he’d go all-in postflop in a 4 SPR pot without a hand that beats QQ…it pushes me away from automatically committing it postflop. Like anything in poker, think ahead and consider how automatically committed you’d be postflop, if that’s good for your hand, and how tight or wide villain would stack off postflop in that SPR. Fish don’t understand SPR but good players do!
SPR is a powerful concept that helps us gauge how automatically committed we are, or aren’t, to a given pot. As a general rule we want to enter smaller SPR pots with strong hands and stay away from smaller SPR pots with smaller pairs, suited connectors, and junky broadway hands. Remember, this is just a primer on SPR and there is much more you can do with it, but just knowing how to calculate it and how enter small SPR pots gives you a leg up on your ignorant opponents. If you have any questions please don’t hesitate to let me know, otherwise good luck and happy grinding!