Suppose you're convinced by the arguments in Part II that MAFIA is worth a try. What adjustments are necessary to the system? What extra benefits does MAFIA confer to the rest of your bidding system?
In this article I describe the main differences between how most North American experts play today, and how I play MAFIA with my regular partner. These are not the only ways to adapt Standard American to the MAFIA style,but I can attest to the effectiveness of these methods.
Delayed Stayman and the 2NT Relay are sufficiently important that I have written a separate article discussing my methods over 1m-1M-1NT. The basics are easy to grasp, but there are a lot of details on the third round of bidding to be spelled out.
I recommend the same form of Delayed Stayman to Traditional and Walsh bidders too, though some of the third-round continuations need to be a little different. The 2NT relay is not necessary in the Traditional or Walsh style.
Fourth Suit Forcing in some form is an essential ingredient of the Traditional and Walsh styles too. As with Delayed Stayman, the exact set of hands you use FSF on, and the third-round bidding after FSF, depend on your system style.
The need for FSF can be best illustrated by looking at 4 possible hands for responder. Suppose the bidding starts 1H-1S-2C. Responder might hold:
Each of these 4 hands has to be bid via a different sequence -- or else the partnership will have to guess blindly whether or not 4S is a playable game. The jump to 3S has to show six spades -- either hand 3 or hand 4, but not both. My preference, following Traditional practice, is to show hand 4 this way. Most Walsh and 2/1 players do the opposite, and show hand 3 this way.
Either way you play the jump to 3S -- the other 3 hands all needed sorted out! You need to know if opener has 3 spades, and if opener has a bare minimum opening or not. In the event opener doesn't have 3 spades, you want to know if he has a diamond stopper to make 3NT playable, or a sixth heart to make hearts the best contract.
Because FSF has to include some invitational hands like Hand 1 above, and because I advocate opening some hands with as few as 11HCP at the 1-level (see "How light should you open the bidding?"), it is necessary to have precise agreements about what is forcing and what is passable after FSF. Here is how I play:
1H-1S-2C-2D-2S: Opener has shown 3-5-1-4 or 3-5-0-5 shape and a bare minimum hand. Responder, holding 11 points himself, will pass, especially if he has wasted diamond honours opposit opener's shortness. If opener has Hand 2 above, he will continue to 4S, to play.
1H-1S-2C-2D-2NT-3D: Opener has a flat 12HCP or so, and has denied having 2 cards in spades. Responder has a hand with 4 or 5 spades and 5 or 6 diamonds, very unbalanced, warning opener that NT is a dangerous contract. Opener will commonly pass, but occasionally may decide to try 3NT anyway - or even 5D.
1H-1S-2C-2D-2NT-3H: This is how responder shows a limit raise with only 3 hearts (1H-3H would promise 4). Opener chooses 3H, 3NT, or 4H as the final contract.
1D-1H-1S-2C-2D-3NT: Opener has shown 5+ diamonds and 4 spades, denied 3 hearts, and probably doesn't have a club stopper since he didn't bid NT himself. Responder must have a hand like Hand 2 above, game-forcing, that just needed to make a choice between 4S and 3NT.
This only scratches the surface of my FSF style. The main lesson to take away from this section is you need clear agreements with your partner about what happens on the third round after FSF. Most 2/1 pairs would play the example auctions about as forcing, and the corresponding natural jump auctions like 1H-1S-2C-3H as invitational. Even many Traditional pairs play that after FSF, responder must ALWAYS bid a third time. My rule allowing responder to pass in two rare situations is a specific adaptation I make because of opening lighter than most in first and second seat.
Canape jump shifts at responder's rebid, mentioned above, are a logical consequence of MAFIA responses and FSF: a responder with 4-6 shape has to show his 4-card major suit at his first turn, and by failing to ask opener if he has 3-card support via FSF, he suggests he doesn't have a fifth card in his major.
Someday this will be a topic for an article on its own, when I get around to descibing my ideas on how best to respond to 1C-2C and 1D-2D.
If you respond 1D to 1C playing MAFIA, you ostensibly deny possession of a 4-card major. What sort of hand might you have to respond 1D, then?
Type 1 hands respond 1D, then rebid 2D if weak, 3D if strong, or go via some FSF or Delayed Stayman auction if invitational. Types 2-4 require opener to indicate whether his hand is suitable for declaring notrump.
After 1C-1D, opener's rebid of 1H or 1S says "I have this major suit comfortably under control for NT purposes, but the other one is wide open -- unless you have this suit covered, we need to consider playing in a minor suit, or possibly a 4-3 fit in this major." Opener's rebid of 1NT, on the other hand, shows the usual 11-14 points and says "I have both majors under control." Opener may even be 4-4-1-4 and rebid 1NT! Remember, after the 1D bid, opener's primary job is not to show major-suit length -- it is to show suitability for declaring notrump. Opener's rebid of 2C, of course, shows a 6-card suit, and 2D shows 4-card diamond support and implies a fear of notrump.
After 1C-1D-1NT, as over 1C-1M-1NT, responder needs a way to ask if opener is maximum or minimum, to decide whether or not to try 3NT. And responder still needs a way to bid either minor suit, weakly, invitationally, or strongly. For this purpose we can recycle Delayed Stayman and the 2NT Relay!
You've probably noticed that if we always respond 1M with a 4-card major, sequences like 1C-1D-1NT-2H, which show strong 4-5 hands in Traditional bidding, are idle. I take advantage of this idle bid to cure one of the few weaknesses of the Delayed Stayman structure after 1C-1M: responder cannot distinguish between 4-5 and 4-6 shape -- and sometimes can't show his 5-card diamond suit at all after responding in a major. For this reason, I allow a single exception to the MAFIA principle: a hand with a 4-card major and a longer diamond suit, which cannot be easily described after 1C-1M-1NT, may respond 1D.
This leads to a specific and very nonstandard meaning for responder's reverse: 1C-1D-1NT-2H and 1C-1D-1NT-2S are nonforcing and show specifically 4 cards in the major and 5 diamonds, with invitational values; opener chooses the final contract, either in that major, in diamonds, or in NT.
It also leads us to a reason for Delayed Stayman: if responder wants to ask opener about his major suits, and then choose for himself whether to play in the major (possibly a 4-3 fit!), diamonds, or NT, he can. Here is the full set of rebids I use after 1C-1D-1NT-2C:
Some pairs play that opener can bypass a 4-card spade suit to bid 1m-1H-1NT. These pairs typically play some kind of "Delayed Stayman for both majors" all the time.
[This section is incomplete.]