Handicap stones let players of different ranks meet on even terms (AGA Rule 4) — one stone per rank difference is the usual guide; Timed games use byo-yomi (reserve periods) or Fischer increment; time is a tournament regulation, not part of the rules of play
Why people argue about this
People often assume that handicap stones are a fixed number for all rank differences, forgetting that one stone per rank difference is just a common practice, not an absolute rule. This leads to arguments about how many handicap stones should be used when players have significant rank gaps in tournaments.
