progressWhy antes widen your ranges
A small ante changes the price of an open more than almost anything else.
In a tournament with antes every player puts a small amount in before the cards are dealt. In our book the ante is 12.5% of a big blind per player, so an 8-handed table adds 1 big blind of dead money to the blinds.
The steal math
You open to 2 big blinds. If everyone folds you win what is already in the pot. Ignoring what happens when you are called, you break even when folds happen often enough:
| Pot before your open | You risk | Folds needed to break even | |
|---|---|---|---|
| No ante | 1.5 BB | 2 BB | 57.1% |
| 12.5% ante, 8 players | 2.5 BB | 2 BB | 44.4% |
With an ante you need 44.4% folds instead of 57.1%. The difference of about twelve points is the reason many hands that were folds without an ante become raises, and why defending the big blind also becomes easier (the big blind gets a better price to call).
Both sides of the effect
- Openers profit more from a fold, so they can raise more hands, especially from late position.
- Defenders face a bigger pot for the same call, so they must defend wider. Against a button min-raise the big blind needs only about 18% equity.
- Short stacks shove more often, since the dead money is a larger fraction of their stack.
Where to see it
Compare the ranges in our preflop chart library: they are all with a 12.5% ante, so you see the widened ranges directly. Other ante sizes change the numbers, in the same direction.
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Related guides
Questions
How big is the ante in our charts?
12.5% of a big blind per player, which is 1 big blind in total at an 8-player table.
Does the ante change the big blind's defence?
Yes. The pot is bigger, so the big blind needs less equity to call and should defend more hands.
Is the break-even number a full strategy?
No. It only counts the times everyone folds. When you are called, the strength of your hand and the postflop game decide the result.
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progressGTO guides use our own solution book (v13, 8-max tournaments with ante, chip EV): an approximation of equilibrium with a modelled postflop, not an exact solution. Numbers are computed from the book and from the exact ICM model.
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