LearnModule R1 · Betting the river
R1-L4
River bet sizes
How to pick a river bet size from your range's shape: small with thin value, big or an overbet with the nuts and bluffs.
In this lesson
- Bet small when your range holds many thin value hands.
- Bet big or overbet when you hold the nut advantage and enough bluffs.
- Explain why the nuts sometimes bet small.
- Match the size to the hands you want to be called by.
Size follows the shape of the range
A river bet size is a choice about which range you bet with. A polarised range — the strongest hands and bluffs — wants a big bet: the strong hands are paid more, and a bluff-catcher facing it has to decide for a lot. A range of thinner value hands wants a small one: it is called by the worse hands it beats.
Rail's river solves, which can bet a third, three quarters or one and a half pots or go all-in, sort the classes that way. The strongest hands use the big sizes and the overbet most; for top pairs and two pairs the small size is a far larger share of their bets; the bluffs bet big alongside the nuts.
The price of each size
A bluff of a third of the pot, 6.6 bb into 20 bb, needs folds about 24.8% of the time. An overbet of 30 bb into 20 bb needs 30 / 50 = 60%, and the caller must defend only 20 / 50 = 40% of its range to stop it.
So an overbet only works where the caller's range is full of hands that must fold to it: when it is capped. In position after a check is the usual place, and Rail's solve overbets there noticeably more often than out of position as the first to act.
- MDF: defend at least
- 40%
- Alpha: folds needed
- 60%
- Caller needs
- 37.5%
Why the nuts sometimes bet small
If every small bet were thin value, the opponent could raise it every time. Rail's solve keeps some of its strongest hands in the small size for that reason: the small bet carries a few hands that are happy to be raised.
Rules of thumb
- Polarised range, big bet; thin value, small bet.
- Overbet when the other range is capped and yours holds the nuts.
- A third-pot bluff needs about a quarter of folds; an overbet of one and a half pots needs 60%.
- Keep a few strong hands in the small size.
When they break
- Against a player who calls any size with any pair, size up your value and stop overbet bluffs.
- Against one who folds to big bets and calls small ones, bluff big and value-bet small.
Example hands
Examples come from two places only: your own analysed hands in this lesson's spots, and a hand Rail deals and grades itself. Never a hand from outside Rail.
Sign in, with analysed hands, to see examples from your own play here.
Rail scripts this hand from the lesson's own practice, always the same one, and grades it with the analysis. Decide first, then read Rail's verdict.
Practice
The lesson is mastered when every exercise below that Rail can grade is passed. Missed items come back later as review cards.
Exercise 1
Pass: 3 of 3 rightThree rivers in position after a check: put each hand class into check, small, big or overbet, graded class by class.
Exercise 2
Pass: 3 of 5 rightFive river decisions, dealt hands where Rail's solve mixes its sizes.
Exercise 3
OptionalYour own first river decisions, the costliest first.
Sign in to practise on your own hands.
Module R1 review · Betting the river
6 items mixed across this module's lessons: a spot from one lesson, a sum from another. Telling which idea a spot asks for is half of it. Missed items join your review cards; the score is not kept.