Arrow Switching

At the Manly Leagues Bridge Club, we have often had difficulties achieving balanced NS and EW fields by seeding - there are often pairs who "need" to sit NS or EW for medical or strong personal preference reasons. Consequently we have begun using arrow switches to achieve a fair result across the entire field rather than seeding to achieve balance between the two directions.

A question often asked is why we only need one (or two) arrow-switched rounds. In simple terms the reason is that it takes the majority of the rounds to adequately discriminate between all the pairs in a direction, but the arrow switch round is only trying to discriminate between the two fields and has say ten matches between the two fields going on in the last round to do this.

There are some great articles for those more interested in the maths.