In no-limit poker the abstraction is a few fixed multiples of the blinds if you're leading out from a reasonably sized stack (1x big blind through maybe 6x big blind) or a few fractions of the pot if you're raising or betting in a later round (1/5, 1/4, 1/3, 1/2, 2/3, 3/4 or 1x the pot, or all-in).
That's really interesting and something I never knew. Is that just something to simplify writing a decent bot, or is that something human players think in terms of?
Humans need to simplify the game more than bots do, really. Bots can calculate exact odds ratios. Humans do rough estimates, because that's faster. Also, you don't need exact odds as it's common to bet such that your opponent doesn't have the correct odds to call.
