Neuberg formula

In duplicate bridge pairs tournaments, the Neuberg formula is a method of adjusting match point scores achieved on boards which have been played fewer times than other boards. Originally developed by Gérard Neuberg of France, its objective is to achieve a formula for the final score of every pair to which each hand they have played contributes with equal weight.^[1]

Although the objective behind the formula is of questionable soundness, the formula itself follows from well-defined mathematical assumptions, and is almost universally applied in computer-scored bridge tournaments.

A board might have been played fewer times than others because:

• the movement was not completed, or
• there was a phantom pair, or
• one or more plays of that board had to be cancelled because of irregularities, entailing explicit percentage assignments for those plays.