The original Symmetric system, as set out in the book by Roy Kerr and Walt Jones, was based on Precision, a strong club with five-card majors. Within a few years a revolution was underway with both the base (forcing pass or strong club) and the extent of the MAFIA principle (majors first always) varying. The national then international success of Paul Marston and Stephen Burgess led to many other (mainly younger) Australian and New Zealand players experimenting with a number of systems that used symmetric relays.
Moscito is principally associated with Paul Marston, who represented Australia with a range of partners playing the system he helped to create. It is essentially a strong-club adaptation of the symmetric forcing pass system he played successfully with Stephen Burgess for many years in the 1980s. The opening bids underwent numerous changes over the decades but always retained the priority given to showing a four-card major before other features — although by the 2000s Marston was allowing opener discretion with a six+card minor or when balanced. Here are Marston’s notes for a transfer-based opening structure from 2004, 2005 and 2007.
Moscito versions and variants proliferated, often with different names and frequently with different opening-bid structures, especially in jurisdictions where transfer openings were/are illegal. Some of the best are:
SCAMP is Nick Hughes’ Moscito variant that retains an opening bid (1♠) to show hands with both majors but separates out the hands without a major (into BAL or a long minor). Hands with spades but without hearts open 1♦. It drew on the Eclectic Symmetric Pass that Nick and I played in the early 1980s. Nick emphasises simplicity, and consistency with the forcing pass version (SPAM). I prefer more detail, and adapted a number of Bo-Yin Yang’s ideas from Terrorist Moscito (see below). My notes are MUCH longer than Nick’s. It’s worth noting that Nick has been regularly playing SCAMP since the late 1980s and has perhaps played more boards using a relay system than any other player . . .
Terrorist’s Moscito is an adaptation by Bo-Yin Yang that retains the old opening structure where 1♦ denies a four+card major, 1M shows that major and denies the other major, and 1N shows both majors. All two-level openings are weak. Interesting features include:
- the use of 3-2-1 points, but with a a deduction of 1 for a singleton honour, including a singleton A, as the principal form of hand evaluation for opening bids and responses;
- an excellent transfer-based response structure after opening 1N to show both majors;
- a major tweak of the shape-showing structure to incorporate stronger balanced hands (the 2♣ response was limited to balanced hands with 5-7RP);
- a comprehensive set of relay relay breaks for opener after the 2♣ response (balanced hands with 5-7RP), as well as a clever shape-showing structure designed to maximise the transfer effect when responder has a three- or four-card major;
- an intriguing method of denial cue bidding that prioritised controls when teller had 8+RP (by 2003 BY was using parity cue bids);
- the best structure for finding major-suit fits after a negative response to a strong club; and
- the widespread use of Rubensohl-like methods in competitive auctions, including by a strong-club opener.
Moscito Byte (Moscito for GIB) was a project BY and I collaborated on at the request of Matt Ginsberg, the developer of GIB. It is an amalgam of our ideas with the (often-excruciating) detail required for programming a computer — the notes could not say simply that with a freak shape teller should find one with a similar structure (e.g. treat a 7510 as a 5431) then make an impossible bid. The version actually implemented in GIB drew heavily on this document.
The Way Forward was an innovative British symmetric variant from the mid-1990s that drew on then-popular British four-card major methods. Unusually, it featured different major-suit openings, each with a thought-provoking rationale. The symmetric structure was tweaked to separate out hands with voids. (Handling voids was a theme of the system: asker’s breaks when relaying showed voids with the aim of better handling a set of problem hands for relay systems.) I’m not convinced the price of doing so — pushing other shapes up one step — was worthwhile. Also intriguing were the honour-showing and honour-locating methods used. I think users would require considerable practice to make make best use of them, especially the multiple terminator puppets.
IMPrecision is a symmetric Precision variant developed by Sam Ieong and Adam Meyerson. This is one of the best systems ever, in my opinion: excellent design decisions with significant improvements over standard methods in a number of areas. As well, the system notes are clear and comprehensive, and set out the theoretical rationale for the key system choices.
The big idea is that most of the responses to a strong club should show semi-positive or minimum game-forcing hands. These are the deals where competition is likely so responder should show something about shape before the opponents intervene. This means that the 1♣ opener has available (and needs) a wide range of chain breaks, especially to cater for minimum-strength openings.
A consequence of this response structure is that the 1♦ response is either a weak hand (0-4) or a very strong responder (7+RP, where A=3 etc) or a balanced game force. Mostly that works well, including in competition. The downside is that when opener is balanced and responder has a strong shapely hand — the most frequent combination where slam is likely — no relays are possible.
Here are their old notes and my notes, based on what Adam and Sam have shared on Bridgebase Forums, of the changes to auctions after opening one of a major and to Parity Cue Bidding.
Is there a system design change that could address the problem of not relaying when opener is balanced and responder has a strong shapely hand? The answer is “yes”. I’m unable to make public the innovative solution a keen advocate of IMPrecision has developed to address this problem. However, I can say that Brad Coles, my “I’m willing to try anything” partner, and I spent a number of months tinkering with and practising this variation. Alas, our plans to play it in the principal national teams championship were derailed when my first kidney transplant failed, but our practice showed that the solution is an improvement at the cost of a substantial memory load.
Relay Systems and More 