Stack-to-Pot Ratio, Part 4: Planning Hands with SPR

Before I get fully into this Part 4 installment on SPR, I need to clarify something from the previous post. The examples I gave in the Part 3 (here) make it appear that one uses SPR as a means of evaluating a shove after the flop. While this is technically correct, it's also a bit misleading. A better way to think of SPR is as a preflop decision making tool to pre-determine what you're going to do with your hand. I.e., it's main function is for planning a hand before the flop, not after.

Which brings us to this installment on SPR: planning hands with SPR.

There are two main things that evaluating your SPR helps you do preflop: a) decide whether you should even enter the pot in the first place; and b) tailor your preflop raise sizes to set up good SPRs for the type of hand you hold. Let's look at each of these:

Decision to Enter a Pot
Let's say you're in a $0.1/$0.25 ($25NL) 9-handed NL cash game. You're in the big blind with 3♣3♦ and there is a solid mid-position player who open raises to $0.80. Everyone else folds, and the action is to you. Let's look at two scenarios:

• Low SPR. You have a full stack, but your opponent has a pre-action stack size of just $7.50, or 30bb. We start the REDi process with R is for Reads, and we put our opponent on medium to large pairs and big overcards, like AJs+, KQs, and the like. We're getting ~9.5:1 implied odds, which is higher than the theoretical 8:1 needed to set mine, so we might be tempted to call here and try to hit one of the two remaining threes in the deck. Ah, but a few things work against this approach. First, you're up against a solid player who is less likely to pay you off. Second, you're OOP against this player. And third, your hand doesn't fit the SPR guidelines for drawing hands we outlined in the previous post. Specifically, our SPR is ($7.50 - $0.8) / ($0.80 + $0.25 + $0.10) = 5.8, which falls into the "low" category. Per the SPR guidelines, low SPRs work best for big pairs and large overcards, neither of which we have. This is therefore a relatively easy fold.
• High SPR. This time both us and our opponent have 200bb deep stacks, or $50. Yes, we're still OOP and our opponent may not pay us off if we hit, but we're getting ~60:1 implied odds, which is very good. Further, our SPR is ($50 - $0.80) / ($0.80 + $0.25 + $0.10) = 42, which is considered "high." High SPRs are hand made for big implied hands like this, so this is an easy call.*

Tailoring Raise Sizes**
When you get a chance to choose a bet or raise size preflop, you should think about what kind of SPR you're offering your opponent and yourself, and then try to tailor your sizing accordingly. Let's again look at two different examples to illustrate the point:

• Raising 3x. You're in a $0.5/$1 cash game in MP. Everyone has 100bb, or $100 stacks. The action folds to you. You've been dealt A♦K♣ in MP. You raise to the standard 3xbb, or $3. If you get called by, say, the button (i.e., not reraised) your SPR is going to be ($100 - $3) / ($3 + $3 + $0.50 + $1) = 13. This is solidly in the "medium" range of SPRs, which does not do very well with TPTK-type hands, which is what you will most likely have if you hit the flop. In this situation, you need to be fairly cautious post-flop, and you must be willing to dump your hand if the opp gets crazy and starts 3betting and raising, representing big strength. In other words, SPR says that the risk is too great for the reward with this type of hand on a flop when you only have TPTK. Folding, or pot control will be your friends here.
• Raising 7x. Same scenario as above, but this time you raise to 7xbb or $7. Now your SPR is going to be ($100 - $7) / ($7 + $7 + $0.5 + $1) = 6. This is now a much better SPR for TPTK-type hands, so you would/should be willing to get it all in on the flop if your opponent wants to play ball.

Some Final Thoughts
Stack-to-Pot Ratios are yet another tool you can use to help plan hands and make your post-flop decisions easier. That said, SPR is not one The One Great Thing that will turn you into a winning poker player; i.e., it's just another weapon in your arsenal. Too many people rely either too heavily on its use, or they ignore it altogether. Both approaches are obviously wrong. Also, you aren't always going to be able to manipulate your opponents quite so easily as demonstrated in the examples above. The good players you face at the mid-stakes and above level are also aware of SPR, and they will be tailoring their own raise sizes, and planning their own hands, based on their hand types and desired SPRs. Proceed with caution.

All-in for now...
-Bug
*Actually, I might be tempted to raise here and take control in the hand. I'm OOP, so I want to maximize other edges I have available to me. Initiative is one of these, as is fold equity, so I"m probably raising if I actually decide to play this hand....
**When tailoring raise sizes, you need to be very careful of giving away your hand via your bet size. One of the common leaks that beginners make is betting big with strong hands and small with weak hands. Good players will quickly pick up on this and eat your lunch. One of the ways of countering this is to occasionally mix up bet sizes independent of your hand strength, keep all your bet sizes the same, or only tailor bet sizes against weaker, non-L2 players. In other words, this is just another way of saying don't blindly use SPR as the end-all/be-all approach to selecting bet sizing.