Table Stacking:  The ACBL masterpoint (MP) award in an Open game is  0.1 MP per table.  Table stacking was invented because Open game MPs were slashed when a Limited game ran.  20 table Open became 10 because the Limited game (e.g., 599) running at about the same time drew 10 tables away from the Open.  To maintain the Open game MP award, the ACBL adds the tables from the Limited games to the Open game.  For example:  if a 99 game has 10 tables, a 599 game has 10 tables and Open has 10 tables, the Open game MP award will be based on 30 tables giving a 3.0 MP overall strat A award vs 1.0 MP without table stacking.  ACBL has capped VACB online game MP award at 2.5

Limited Game MP awards are a percentage of Open Game MP awards: 80% if the limit is 300+ , 70% if 200-299, 60% if 50-199, 50% 20-49, 40% if 10-19, and 30% if 0-9