About a quarter of hands: every pair, every suited ace, broad suited coverage, the standard offsuit steals.
The reference tier. Standard live full-ring opening ranges: value-weighted, position-sensitive, no limping.
The cutoff attacks the button and the blinds. This is the first position where pure steal equity carries a meaningful share of the range.
Assumes a live-standard open to ~4bb, raise-or-fold. In straddled games, halve your effective big blinds and read the chart at that depth.