Polarised range

A polarised range sits at two extremes of strength: hands you are happy to get all the money in with, and hands with little or no showdown value that only win if the opponent folds. There is almost nothing in the middle, because medium-strength hands usually prefer to check rather than join either extreme. Both halves want the same thing, a big pot for the value hands and maximum pressure for the bluffs, so a polarised range likes to bet large, often three-quarters of the pot or more.

Worked example. On the river your betting range is two sets and two missed flush draws. The sets want to build the biggest pot they can win, and the missed draws have no showdown value and only profit if the bet forces a fold. Both halves are best served by the same big size, so the whole range bets one way: large.