Since many games pose no difficulty for formula_13, the table is chosen so that no outcome is repeated in any column, which ensures that in the corresponding game any change in formula_12's move means a change in outcome, unless formula_13 has a move to keep the outcome from changing. With this restriction, if formula_13 never changes moves, the outcome fully depends on formula_12's choice, while if multiple moves are available to formula_13 it can reduce the variety of outcomes, if the table allows it, dividing by as much as its own variety of moves.