Mau makes light overcalls - 6 to 15 points; the objective is often lead directing.
The suit should be of good quality.
There are various ways of responding to an overcall - a simple way is to play a new suit as
forcing for one round and a jump raise as weak.
Mau treats a response in a new suit as non-forcing but constructive.
Mau uses light preempts and Namyats.
A hand containing a long strong major suit ( min KQJxxxx ) and 7.5 to 8.5 tricks
is opened with 2-under Namyats.
A response of 4 of the major is to play;
A response of the intermediate suit is a transfer.
Responder will then decide whether to pass or proceed to slam.
A response of 4NT is RKCB;
Responder may also start with the intermediate suit and cuebid to slam.
Mau uses 3NT as minor suit Namyats.
In response 4C is used as "pass or correct";
4D/4H/4S as first round control showing with slam interest;
5C as "pass or correct";
When an opponent bids a minor, the direct cuebid shows a major two-suiter.
When an opponent bids a major, the direct cuebid shows the other major and a minor.
( Responder bids 2N to ask for the minor )
The convention was devised by Michael Michaels of Florida and is called Michaels.
The hand should be at least 5-5 in the two suits; the point range is either 6 - 10 or
15+.
If the point range is 11 - 15, it is better to bid the suits naturally.
After opponents opened the bidding, the scheme of No Trump responses is as follows:
In the direct seat, the range is 14 - 18 points and all Systems are on.
( Some experts use non-forcing and forcing stayman and do not use transfers over NT overcall.
Their objective is to make the opponent, with the opening hand, lead )
In the balancing seat the range is 11 - 14 points (borrowed Ace).
A jump to 2 NT is used to show a weak hand with the two lowest unbid suits.
When opponents open 1 No Trump, there are several ways of competing.
Because of the proliferation of Weak No Trumps, it is better to device two schemes for
competing.
If the opponents play weak No Trump (upper limit of range is 15 points or less),
a double is takeout and other bids are natural. Partner could convert the double to
penalties.
If the opponents play a strong No Trump (upper limit of range is 16 points or more)
Mau uses WONT.
To comply with the ACBL General Convention chart, the meanings of the 2C and 2D bid have been
flipped: