The A, B, and C columns show which stratum each pair is in. In stratified games, players are grouped into three strata based on their combined ACBL Masterpoints:
- Stratum A – the highest-ranked pairs
- Stratum B – mid-ranked pairs
- Stratum C – the lowest-ranked pairs
If a player doesn’t have an ACBL number on file, their pair is placed in Stratum A by default, to prevent experienced but untracked players from competing in lower strata.
Stratification helps increase masterpoint awards by giving lower-ranked players more chances to win. Instead of only competing against top players, they also compete within their own stratum — against others with similar experience and masterpoint holdings.
- All players compete for A stratum points
- Pairs in B and C also compete for B points
- Only C pairs compete for C points