DISCLOSURE OF SYSTEMS AND CONVENTIONS - (updated January 2015)
The principle of adequate disclosure requires that competitors fully disclose all conventions and treatments requiring defensive preparation. In addition to the Simple System Disclosures (SSDs), pairs should use SSD Extras (when introduced) or Standard Messages to achieve this objective.
ALERTING IN BCL
Unless otherwise stated, we follow the WBF Regulations on alerting. The WBF Regulations are reproduced below in blue. BCL interpretations and exceptions are shown in black.
1. Full disclosure is vital. Players are expected to protect themselves to a large extent. They are also expected to observe the spirit of the Laws as well as the letter.
2. The Policy has been made as simple as possible. Players are, however, expected to alert whenever there is doubt.
The following classes of calls should be alerted:
1. Conventional bids should be alerted, non-conventional bids should not.
2. Those bids which have special meanings or which are based on or lead to special understandings between the partners. (A player may not make a call or play based on a special partnership understanding unless an opposing pair may reasonably be expected to understand its meaning, or unless his side discloses the use of such call or play in accordance with the regulations of the sponsoring organization). See Law 40(b).
3. Non-forcing jump changes of suit responses to opening bids or overcalls, and non-forcing new suit responses by an unpassed hand to opening bids of one of a suit.
Do NOT alert the following:
1. All doubles except very unusual doubles – see below.
2. Any no-trump bid which suggests a balanced or semi-balanced hand, or suggests a no-trump contract.
3. Any call at the four level or higher, with the exception of conventional calls on the first round of the auction.
Nevertheless, players must respect the spirit of the Policy as well as the letter.
This means that you …..
Don’t alert doubles unless they have very unusual meanings. Very unusual doubles include (and are not limited to):
Don't alert NT openings if they are natural and balanced, but do alert if you have an agreement that you may hold a singleton (in which case, it isn’t balanced). Do alert a 2NT opening that shows the minors
FINAL WORD OF ADVICE
Alerts are there to help and inform. They are not there so you can score bridge-lawyering points off opponents who don't alert "obvious" alertable calls like some above
The general rule is "if not sure then alert"
Then, if you are declarer or dummy, explain anything that you think opponents may not know before the opening lead. But if you are defending, don't explain (as it gives Unauthorised Information (UI)) until end of play.