[par31]

Someone at the club asked me the following last week. He wanted to know the rules about playing a 10-12 1NT opening in an EBU level 4 event. In particular, is he forbidden from agreeing to open a 4333 10-count 1NT in 1st or 2nd position?

I thought the answer to this was obviously no, but on checking the EBU blue book it says "All one-level opening bids, whether forcing or not, must by agreement show 8+ HCP and, in first and second position, follow the Rule of 18. Natural 1NT opening bids must show 9+ HCP." (7A3). This suggests that it is indeed forbidden as it doesn't satisfy the rule of 18.

Is this really what the regulation is intended to say or have the words "in a suit" been accidentally omitted in the first sentence? The latter seems more likely to me, particularly as opening 4333 10-counts 1NT appears to be permitted at level 2: here, the relevant blue book extracts are "A one-level opening bid in a suit must either show 11+ HCP, or show 8+ HCP and satisfy the Rule of 19." (6C1) and "An opening 1NT must be non-forcing. It may show any agreed range with at least 10 HCP, with no singleton or void and no 7-card suit." (6C2)

[FrancesHinden]

Any 9+ natural 1NT opening is permitted at any level.