The client GetLeaderboard command has a limit of 100 entries. Is the Server call limited the same way? The API reference doesn't specify a limit, and has the number of entries as a required field.
(most likely, we won't do this as a full-server pull, and instead resort to pulling that data per player after each game, as we only need it for the top 1% or so of players, but it'd be good to know anyway)