Source:
THE VILLAGES DUPLICATE BRIDGE CLUB
A convention commonly used over preempts is the Leaping Michaels convention. It is a conventional overcall made in defense to an opposing 2-level or 3-level preempt. Leaping Michaels is played by many pairs as it provides a means to show very strong game forcing two-suited hands (5-5 or longer) that are less suitable than using a takeout double.
If you currently play 2/1 using Michael cuebids, you may want to consider add the Leaping Michaels Convention.Leaping Michaels, utilizes the 4

and 4

bids. Similar to the Michaels cuebid, in case this minor suit overcall is in the opposing suit, both major suits are implied. In case the overcall is not a cuebid, the suit bid plus a major suit is indicated. So, on preempts of the opponents (indicated between brackets), the following applies when playing Leaping Michaels:
(2/3

) – 4

: Clubs and spades
(2/3

) – 4

: Diamonds and spades
(2/3

) – 4

: Clubs and hearts
(2/3

) – 4

: Diamonds and hearts
(3

) – 4

: Majors
(3

) – 4

: Diamonds and an undisclosed major
(3

) – 4

: Clubs and an undisclosed major
(3

) – 4

: Majors
After 3

or 4

, the bid of 4

asks for a major. The bids 4

and 4

are to play. Following 3

or 4

, the bid of 4

is played as passor-correct.
Some partnerships prefer to interchange the meanings of the 4

and 4

bids following a 3

preempt so that 4

denotes diamonds and an undisclosed major. This has the advantage that the 4

becomes available to ask for the major suit. The 4

/4

responses may then be played as natural (to play).
Discuss this with your partner!
Leaping Michaels can be utilized after natural two-level preempts and also after conventional preempts such as the Muiderberg convention, also called the Dutch Two opening. It is a preemptive opening based on a two-suiter with precisely a five-card major and a minor suit (four-cards or longer).
In Muiderberg the 2

opening denotes five hearts and an unknown minor suit, while 2

denotes five spades and an unknown minor suit. It can also be played over the Multi 2 diamonds preempt which shows a weak two bid in either major. Here Leaping Michaels can be utilized to good effect:
(2

) – 4

: Clubs and an undisclosed major (4

asks for the major)
(2

) – 4

: Diamonds and an undisclosed major (4

is pass-or-correct).