What is SPR?

Recently I've noticed thread around that have statements like "Top pair with a SPR of 5.1 is good"

What is SPR?

Stack to pot ratio. Mentioned (maybe coined?) in Ed Miller's Professional No-Limit Holdem.

I have yet to pick the book up, but SPR (or committedness) is a HUGE concept in ring games/deep stacked games period.

As Chuck said it's stack to pot ratio and is a huge topic in Professional No-Limit Holdem. Specifically it's the ratio of the total preflop pot to the effective remaining stack. So if you're playing a NL100 game (with $100 effective stacks) and raise from the sb to $5 and get called by the bb the SPR for this hand is 9.5 ($95 remaining to $10 preflop pot).

The authors suggest using SPR to plan your hands around commitment (or to avoid commitment). Against average opponents they suggest that you should generally commit with TP if your SPR is 4 (or below). That's 2 pot sized bets (preflop pot = 1P, so 1P on flop and 3P on turn). They also say that a SPR of 13 is BAD for TP hands, because that's 3 pot sized bets (river would be 9x the preflop pot) and they say that in general TP hands perform poorly in these situations because they cause TP hands to make poor decisions. Either committing too much with TP or folding the best hand to a big raise on the river.

It's an interesting concept and definitely makes you think more about your hand and how it may play out before you ever put a chip in the middle. I do recommend reading it but if you're a thick as I am it will take several reads before the concepts really start to make sense.

Sorry to bump such an ancient thread! Presumably it's the ratio of the total preflop pot to MY effective remaining stack?Is that for a SPR of 13 or more?

The effective stack size is determined by the smaller remaining stack. So it might be your stack or your opponents. You can also have drastically different SPRs in play in multiway pots. Say pot is $10. You have $100. Opp 1 has $300. Opp 2 has $20. Your SPR with Opp 1 is 10 and is based on your stack. Your SPR with opp 2 is 2 and is based on his stack. You need to care a lot more about opp 1 than you do opp 2!

As for 13 or MORE. TP hands fear the number 13 when it comes to SPR specifically because that is 3 pot sized bets. When expressed as multiples of the preflop size that's 1x on flop, 3x on turn, 9x on river. It's pretty hard to overbet the pot and still get calls by TP hands against most opponents so SPRs over 13 don't really matter much since you're unlikely to get all the money in anyway. SPRs of at least 15 are where you should start looking to set mine.