Two Over One

Two Over One is a standard Duplicate bidding system used by many Duplicate players in the USA. If you elect not to play Two Over One, you'll have to play against it about 75% of the time, so you'll need to know how it works.

It's very close to Standard American --
most of the calls using Two Over One are the same ones you would make playing 'Standard'.

The difference is Two Over One is much more precise for the hard bids -- the in-between counts, slams and competitive part scores.

This section is organized by types of opening, because that determines the entire course of the subsequent auction.