+==== brisk/table/user relationships ====
+
+=== in the room ===
+
+// when standup
+bri->user[user_idx] = user
+user->idx = user_idx
+user->idx_orig = user_idx
+
+// when sitdown
+table->player[player_idx] = user_idx
+user->table_pos = player_idx
+
+=== in the game ===
+
+bin5->user[user_idx] = user
+table->player[player_idx] = user_idx
+user->table_pos = player_idx
+
+