What are the best MLS props to compare in the regular season and play-offs?

Direct answer

Start with scorer, shots or saves markets using the same data source and period. During play-offs, read match-result, shootout and series-advance rules separately.

What to check

MLS has published a best-of-three Round One format. A win in the series and a result in one match need not use the same scope as your selected prop.

Sources and rules

MLS competition guidelines
IFAB rules on match outcomes and shootouts
DraftKings soccer market rules example

Specific bet-slip questions

Does a card after a player is substituted count for an MLS player card prop?

Check whether your ticket counts bookings for a named player, team bookings or only cards shown during active participation. Operators can handle a substituted player’s bench card differently.