A polar bet range is strong hands + bluffs (misses medium). A linear range is a continuum of value. River overbets are often polar; small bets can be linear.
If buddy says every big bet is bluff or every big bet is nuts, fail Grade 4 — size + player type decide range shape.
If buddy says every big bet is bluff or every big bet is nuts, fail Grade 4 — size + player type decide range shape.