Acol Binary Diamond System With Comparative Evaluation

The Acol Binary Diamond (ABD) bidding system provides a better Value versus Complexity profile than Acol, 2/1, or Precision systems. It was developed in Canada, a 4-card-major system that uses a unique 3-tiered strength structure for primary opening bids - 11-14, 15-17, and 18+ HCP. The 15-17 tier has either a balanced 1NT bid or an unbalanced 1D artificial bid which is, hence, the "binary" bid. This system is a variant based on the original Binary Diamond 5-card-major version which was first played in November 2022. The system, compliant with regulations of both the ACBL and EBU, is being played with excellent results in clubs in Canada and England by a small number of intermediate and advanced players. The ABD system is detailed in this book to help you understand the structure and function of the bids. There is also a full comparison of the Value and Complexity of the system versus 2/1, Acol, and Precision, based on extensive simulations. ABD ranks similar for intrinsic Complexity against 2/1 and Acol, with Precision being more complex. But ABD ranks higher in Value than the other three systems. On balance ABD ranks best for Value versus Complexity among the group. Intermediate and advanced club/tournament players would find this system of interest, especially Acol and Precision players. The adoption complexity for Acol and Precision players is less difficult than for 2/1 players. Skilled players will appreciate the strength-zone clarity, early major-fit detection/negation, exact support ranges, and structured interference methods. The system is effective in MP play and is well-tuned to benefit IMP play.