A thin value bet is a value bet with a small margin: a marginal made hand — weak top pair, second pair, a small overpair — bet because, when called, it is ahead slightly more than half the time.
Two things make thin value work more often: a small bet, because a small bet is called by more weak hands, and a villain who has already shown weakness by checking. Thin bets are usually a third to a half of the pot — the size a worse pair can still pay. The best targets are capped ranges: when villain checks a street on which his strong hands would have bet, what remains is medium pairs that can call but not raise. A turn that went check-check is the clearest signal, and calling stations are the other target — against them second pair can bet, because they pay with third pair and ace-high.
The board must cooperate. When the river completes obvious draws, the hands that call a bet are no longer worse than yours. And a thin bet that gets raised is near the bottom of what you can hold: river raises are rarely bluffs, so folding is the standard line. Checking back every one-pair hand ‘because I might be beaten’ gives away money every time worse hands would have called.
Worked example
FAQ
What hands can bet for thin value?
Weak top pair, second pair and small overpairs — but only when worse hands will call more often than better ones. After villain checks, against a calling station, or after a check-check turn, the margin usually tips your way.
When should you not bet thin?
When the river completes obvious draws, when you are first to act with a hand that only better hands call, and against an opponent whose calls are always strong. Then check and take the showdown.