In online poker games, your open size is not a style preference, it is an EV decision. You are buying the right to realize equity, to leverage position, and to create fold equity. If you size poorly, you force your range into bad SPRs, you invite the wrong callers, and you hand the blinds a better price than they deserve.
We are going to treat open sizing like a tool. The tool changes based on position, who is left to act, stack depth, and the rake environment. Your goal is simple, build pots when you have the range edge, and keep pots controlled when you do not.
What Your Open Size Is Trying to Do
An open raise has three jobs. First, it can win the pot immediately. Second, it sets the price for the blinds to defend. Third, it shapes the stack to pot ratio for postflop play, which decides how often one pair hands can stack off and how valuable draws become.
When you multi table online, you want a sizing system that is consistent and hard to exploit. Consistency does not mean one size for every seat. It means your sizes make sense, and you have a clear reason when you change them.
- Smaller opens keep ranges wider, reduce variance, and punish over folding blinds by letting you steal more often for a lower price.
- Bigger opens push more fold equity preflop, deny equity to the blinds, and create bigger pots when you expect to be called by weaker ranges.
The Default Sizing Framework
At 100bb effective, most online pools converge on small opens because people defend blinds too wide and rake exists. Rake rewards pots that end fast and punishes bloated multi street marginal spots. That said, rake is only one variable. Position and opponent behavior matter just as much.
Here is the clean framework I want you to start with, then we modify from there.
- UTG to HJ: 2.0x to 2.3x
- CO: 2.2x to 2.5x
- BTN: 2.0x to 2.3x
- SB vs BB: 2.5x to 3.5x depending on BB tendencies
Notice the button is not automatically a bigger size. On BTN you already have position and a wide range. Your edge comes from realization and pressure postflop, not from charging yourself extra to steal.
Why Small Opens Work So Well Online
Let us talk math without getting lost in equations. When you open 2.0x on the button, you risk 2bb to win 1.5bb. You need folds often enough to show immediate profit, and you also realize equity well when called because you are in position.
If you open bigger, you do not win much more when everyone folds, you still win the same 1.5bb. What changes is how expensive it is when you get 3 bet, and how large the pot becomes when the big blind defends with hands that play well versus wide ranges.
Small opens are also robust versus strong opponents. If a thinking reg starts 3 betting more, your smaller open reduces how much you bleed when you fold, and it makes your defend versus 3 bets a little easier because the pot is not as inflated.
When You Should Size Up
Context dictates strategy. There are spots where you should lean larger because the population response is predictable.
- Versus fit or fold blinds. If the blinds over fold, you can raise a bit bigger and still profit. You are buying more immediate fold equity, and you do not get punished by calls.
- Versus weak callers. If a player calls too much and plays passively postflop, you want a bigger pot with your value hands and your strong draws. You are not trying to win the blinds, you are trying to win their stack.
- In the small blind. You are out of position the entire hand, so you want to deny the big blind a cheap defend. A bigger size reduces their ability to realize equity with trash.
Be careful with the common leak of sizing up only with premiums. Most online sites have player pools that notice patterns quickly, especially at mid to high stakes. Keep your sizing tied to position and opponent type, not your exact hand.
When You Should Size Down
There are also clear situations where smaller is better, even if it feels counterintuitive.
- When aggressive 3 bettors are behind you. Who is left to act is critical. If the blinds or players behind are attacking opens hard, smaller opens reduce your cost of getting pushed off your equity.
- When the table is tough. Against strong defenders, bloating pots preflop just leads to harder postflop decisions with marginal hands.
- When you are opening wide. On BTN, your range includes many hands that benefit from seeing flops cheaply. You still apply pressure postflop, but you do not need to overpay preflop to do it.
Small does not mean weak. It means you are letting position and initiative do the heavy lifting.
Open Size, SPR, and Hand Classes
Relative strength is everything. Different hands want different postflop geometries. Your open sizing influences that, even before the flop hits.
- High card and broadway hands like AKs, AQs, KQs love lower SPRs because top pair becomes more stackable.
- Suited connectors like 87s like deeper SPRs because implied odds and maneuverability matter.
- Small pairs do not want you to “set mine” passively. If you are opening them, you need a plan to win without a set through c betting and barreling in good textures.
That is why we do not justify open sizing with one hand at a time. We size for ranges. Your range composition plus stack depth should create an SPR that your whole strategy can handle.
Hand Scenario: Button Price Tag
Game: 6 max online cash, 100bb effective. Hero is on the BTN with 8♥ 7♥. Blinds are unknown, standard pool players.
Preflop: Folds to Hero. Hero opens to 2.2bb. SB folds, BB calls.
Flop: Q♠ 9♥ 3♣. Pot is 4.9bb.
Action: BB checks. Hero bets 1.6bb. BB calls.
Turn: 6♦. BB checks. Hero bets 5.4bb.
What this demonstrates: The 2.2x open keeps the pot at a workable SPR where your range can c bet small on the flop, leverage position, and then apply a strong turn barrel when equity improves. If you make it 3.0x preflop, the flop pot is bigger, the big blind is still defending a lot, and you are paying extra rake and variance for a steal that does not scale in reward. Here, the small open buys you more frequent, lower cost attempts to win the pot with initiative.
Common Errors I Want You to Stop Making
- Using one open size everywhere. You are ignoring position and who is left to act, which are two of the biggest EV drivers preflop.
- Sizing up to punish the blinds, then auto folding to 3 bets. You are donating extra chips. If you size bigger, you must have a defend plan.
- Open big because you “want value”. Value comes from building pots against callers who pay you off, not from forcing bigger pots against competent defenders.
- Set mining mentality with small pairs. Open them because they function in your range, not because you hope to flop a set and quit otherwise.
A Simple Adjustment System You Can Run While Multi Tabling
You do not need a complicated tree in real time. Use a basic three lever system.
- Lever 1, Position: earlier equals tighter and slightly bigger, later equals wider and slightly smaller.
- Lever 2, Blinds behavior: over fold equals size up, over defend equals stay small and punish postflop.
- Lever 3, 3 bet pressure behind: high pressure equals reduce size and tighten the weakest opens.
If you do this, your strategy becomes coherent. Your opens, your c bets, and your turn sizing start to line up naturally because you are managing SPR on purpose.
Key Takeaway
Your open raise size is a range tool, not a mood. Default to small, efficient opens in online cash because they protect you versus 3 bets, keep SPR playable, and reduce rake drag. Then size up selectively when the blinds over fold or call too wide, especially from the small blind. Always tie sizing to position, who is left to act, and the postflop plan you are trying to execute.
