ACOL and American Standard, the differences
Most of it's the same, but some of the opening bids are a bit different
SAYC (versus Acol)
- 5-cards are needed to open a Major, whereas Acol requires only 4
- the 1NT opening is Strong (15-17 HCP), whereas with Acol it's weak (12-14)
- 1
/
openings both deny a 5-card Major and ask partner to bid any 4-card Major, whereas with Acol the 1/ openings are natural - 1 also promises 4-card suit, but 1 simply denies a 5-card Major (although there seems to be some dispute about this, depending on which book you read)
- a rebid in or is required if the suit was genuine, whereas no rebid is required with Acol
- re-bidding a Major suit by opener promises 6, whereas with Acol six are only likely when rebid by opener (who has to have a good reason for only having 5).
Are you an SAYC player up against some Acol players? Don't let them fool you. . .download the convention card.
Some myths regarding Acol. Actually. . .
- partner can assume a 5-card Major suit from opener, even though only 4 are promised and required
- immediate support for a Major opening is thus still possible with 3-cards
- some players switch to a strong NT when vulnerable
Some similarities
- almost everything else either is or can be the same
The main advantage of Acol is that the weak 1NT opening is highly pre-emptive, since 12-14 HCP is common and crops up twice as frequently as 15-17. Worry not. Both systems are in use in top class world tournaments, where money and reputation are at stake. For normal mortals, most of it is about personal preference, habit and what your friends use.
Doubling a 1NT opening
Remember that American Standard players don't usually understand the weak NT opening, and will generally fail to punish it correctly when they are strong, for instance doubling when they have 13+ points, asking partner for his strongest suit. They might stumble to a fit, and certainly fail to punish the enemy. Acol players should exploit it ! SAYC players should read on. . .
A double of 1NT should be for penalties.
A double of 1NT says to your partner, "I have a better hand than opener." If RHO's 1NT shows 15-17 HCP, you need 18+ to double. If the 1NT opening is 12-14, then you need 15+.
