What drives card counts
The referee's personal booking rate, the stakes of the match and the pairing history: derbies and relegation battles routinely run hotter than mid-table fixtures. Check both teams' card averages and the head-to-head character before touching the market.
Settlement details matter
Bookmakers differ on whether a second yellow counts as one point or two and whether post-match cards count at all — read the rules of your specific book before comparing lines.