In standard methods after a 1 spade opening and forcing no trump response, opener with an unbalanced hand either makes a wide range two level rebid or forces to game with a jump shift. The jump shift consumes bidding space that is needed to sort out the best fit and may have to be made on a three card suit. If opener makes a two level new suit bid should responder raise whenever he has a fit, or should he wait for limit raise values. These are serious and frequent problems. Over the years a number of conventional treatments have been developed to attempt to solve these problems. The first such solution was the forcing 2 rebid in Kaplan-Sheinwold. William Cole developed a method for showing three card support for responder's suit after the auction started with a 1 opening and 1 response which involved a forcing 2 rebid. The Bart convention after a 1 opening and 1NT response uses a semi-forcing 2 rebid with the structure geared to finding heart fits. Some partnerships use a 2NT rebid over the 1NT response as forcing, allowing limiting the shape of jump rebids (the Mecksroth adjunct). All of these conventions work well on the hand types they are designed to cater to, and less well on others.
The Gazzilli convention attempts to solve the entire spectrum of hands opener may have by using a forcing 2 rebid by opener. Opener's strength is divided into two main categories (11-16 points) or 17+ points. Within the minimum range, it is possible to show some hand patterns with 14-16 HCP and good playing strength. Gazzilli allows you to open one of a major with 15-17 HCP and show that hand type also. Responder's rebids are similarly divided into two groups (assuming a forcing no trump response) of 5-7 HCP or 8+ HCP. Here is how it works:
2 - (alertable) either
a) any 5332 shape hand (including a doubleton club)
b) a hand with 5+ spades and 4+ clubs of 11-16 HCP.
c) hand of 17+ HCP.
2 , 2 - natural rebids with 11-16 HCP
2 - 6+ spades with 11-16 HCP, but some hands in top of range may be bid other ways. Also with a very bad 6-card suit it is recommended you treat hand as a 5332 pattern a) with a 2 rebid
(alertable) conventional rebid showing a hand with 6 spades and a side 4 card suit with 14-16 HCP, values concentrated in the long suits. 65 patterns where the spades are near solid should be permitted also. Responder's rebids
3 - weak, 2+ support, opener will pass if 64
3 - 6+ suit, singleton or void in spades, opener should pass unless he has four diamonds
3 - 6+ suit, perhaps a very good 5-card suit. This bid should probably be forcing, opener raising with 2-card support or rebidding 3 on most others
3NT - 10-11 HCP with stoppers in all unbid suits. Opener should normally pass
4 minor - cue bid of ace with spade fit and slam interest
4 - to play, probably long topless suit
4 - to play, definitely should end the auction
3 - enquiry as to openers side suit, opener rebids his side suit or 3 with side club suit. Responder may pass a 3 rebid, having re-evaluated that he lacks fitting cards. He may also bid 4 of opener's side minor as a forcing bid asking opener to show his side singleton or void.
3, 3 , 3 - hands of 14-16 HCP with at least 55 shape, values concentrated in the long suits (side queens and jacks not counted). Losing trick count of 5 or less. Responders preference to 3 is a virtual signoff, he should generally bid game in a major with two cover cards and a fit. 3NT rebid by responder should be double stoppers in unbid suits. Raise to 4 of minor should be invite, bid of other minor is exploratory (for no trump at three level, for slam in unspecified suit at four level, but assumed to be spades if later 4NT is used, since there is no way to establish spades as fit in a forcing auction). Rebid of 3 is assumed natural inviting opener to raise on a doubleton, but may be an advanced cue bid if responder continues by supporting one of opener's suits.
3 - hand of 14-16 HCP with 6+ good spades (usually 1 loser or less) and about 7 playing tricks. Responder needs 3 possible tricks to raise since there is no possibility of openers hand including a side suit. Responder may however bid 3NT with around 9-11 HCP and all side suits stopped (this does not imply a spade fit, so opener can remove to 4 if his tricks are slow.
3NT - undefined. One possibility is to use this bid to show hands with solid spades and 7-8 fast no trump tricks. If used that way, then a 3 rebid would deny a solid suit, and responder would need at least a doubleton in spades to continue with 3NT.
4 of a new suit - A hand of about 8 playing tricks, 14-16 HCP, very long spades, void in bid suit. e.g. AKQxxxx Kxx void Kxx. This meaning seems preferable to me to using the bid on a freak two suiter, both on frequency and utility.
If responder has a weak hand (5-7 HCP) and 2 or more spades, he will usually rebid 2 to immediately limit his hand. This preference may even be required on a singleton (with 1444 shape). Opener must pass unless he has 17+ HCP, in which case he will continue naturally (much as in standard methods). The Bart method is probably better than Gazzilli on these weak hands, since a Bart 2 rebid (as I play it) does not imply more than minimum values. With 8 or more HCP, responder will usually continue with 2 , a relay bid asking opener to clarify his strength and shape. I think a rebid of 3 over 2 should show a 3-card limit raise of spades (as in standard forcing no trump). This leaves rebids of 2 , 2NT and 3 of a new suit to be defined. 2 should be a hand with a strong preference for hearts over spades (either 6 hearts or 5 hearts and 1 spade) and at most 9 HCP (with the 5-card suit). 3 should be invitational with 9-11 HCP, a good 6-card suit and 2 quick tricks or equivalent. Bidding 2 with this hand type risks being unable to deliver the message if opener continues with a strong rebid. My personal preference is to play 3 of a minor responses to 1 as invitational. With that treatment in place, you can bid 3 of the minor directly over Gazzilli with weak hands that have to play in your suit, and 2 followed by 3 of a minor as mildly invitational. If you play Bergen raises, you may have to rebid 2 on the hopeless hands, 3 of a minor over 2 as mildly invitational (8-9 HCP) and 2followed by 3 (over opener's minimum rebid) as invitational. Balanced invite hands of 10-11 HCP should relay with 2 and continue with 2NT over partner's minimum response. This hand type is easy to handle if opener shows a 17+ hand.
This frees up 2NT for other uses, the best I can think of is a non-invitational hand with at least 5 diamonds and 4 clubs. Opener will then rebid 3 with 4+ clubs, or 3 with 3+ plus diamonds (occasionally only 2 diamonds). With hands of about standard jump shift strength he may continue with 3 , 3 or 3NT. With suitable fitting minor cards, he could also jump rebid to 4 of a minor over 2nt (invitational) or simply bid 5 of the minor). If opener rebids 3 , responder can continue with 3 showing an invite 64 hand. This treatment seems to be an improvement over the handling of minors using Bart.
Opener's rebids fall into 5 strength ranges
1. 2NT shows 15-17 HCP with 5332 shape. Responder may pass or raise, or bid 4 of either major to play. A continuation of 3 should show 5 hearts and ask partner to rebid either 3 (very good 5 card suit) or 3nt with a doubleton heart or 4 of a minor (super max with heart fit) or 4 (3 card fit but not super max). A 3 of a minor rebid over 2NT should be forcing and natural with a 5-card suit, opener may then show a stopper, bid 3nt with good side stoppers, rebid 3 with a good 5-card suit or raise the minor. Responder is captain and will place the final contract.
2. 3 NT shows 18-19 HCP balanced 5332. Responder may then rebid 4 of a minor with slam interest or place the contract. Conceivably you could use transfers after this rebid but I think this risks a memory failure
3. 2 shows hand of 11-14 HCP with either 5332 or 5 spades and 4+ clubs. Since this bid is severely limited responder will usually pass with 2+ spades. With an 11 count or exceptional 10 count including good stoppers and intermediate cards he can try a natural 2NT rebid. Rebids of 3 of a minor or 3 are an attempt to improve the contract, opener should normally pass.
4. Rebids at the 3 level show 17+ points and with one exception are game forcing. 3, 3 and 3 show 55 shapes with 17+ points, responder will usually raise if he can, new suits by responder should be treated as natural, but may be advanced cue bids if the next rebid is in opener's side suit. A new suit bid followed by 4 should be treated as doubleton support, scrambling for the best game. A 3 rebid shows 17+ HCP with 6 spades and fewer then 3 hearts. The reason for the short heart restriction is to avoid missing a better fit in hearts (an important feature also in the Bart method. Responder will usually raise spades, occasionally bidding 3nt (implying in particular heart stoppers) or bid 4 or 4 , cue bids with max values for a spade slam. 4 is probably best reserved as natural, but you could use this also as a cue bid.
5. A 2 rebid shows a hand with 5+ spades and a side 4-card suit, either 17+ or 15-16 with clubs as the side suit. It may also be used with 6 spades and 3 hearts. Responder may then bid a suit of his own (recommended with any one suiter or 5332 hand), bid 2NT with a flat hand asking for a natural rebid (2344 with minor stoppers is the most likely holding) or bid 2 if he wants to hear openers side suit. Opener then continues with 2NT (15-16 with clubs, responders 3 rebid then ends the auction), or 3 , 3 or 3 to show 17+ with the suit bid. Over these bids responder can continue with 3 (doubleton honour support) allowing for opener holding 6 spades or 5 strong spades. A 3NT rebid would strongly suggest a singleton spade. If responder instead bids a new suit at the three level he suggests a double stopper there and no fit. If he raises openers minor rebid he invites opener to cue bid with something extra or bid 5 of the minor otherwise. If responder bids 4 of any lower ranking suit than opener's side suit he is showing a maximum hand with fit for the side suit, and a control in the suit bid. If opener has a 5440 17+ hand he rebids his highest ranking side suit (hearts where applicable) over the relay. If responder then bids 3NT and opener takes out to 4 of a lower ranking suit, he confirms the three-suited hand (this may be something of a guess). If responder has 4 hearts and a 5+ card minor, he should always relay over the 2 rebid.
This auction does not create as many problems for responder as after a 1 spade opening and 1NT response. The main point is that responder can distinguish between courtesy raises of the minor rebid and stronger raises (via an artificial 2 rebid). However if opener has 45 in the majors and lacks the strength for a reverse, he will have to either rebid 2 on a three card suit (if permitted) or 2 on a singleton. If you agree that 2 promises at least 4 cards, then 2 becomes effectively forcing (responder could only logically pass with six card support and a weak hand). Playing standard forcing no trump, after openers 2 rebid responder can rebid 2 not forcing with a six card suit or good five card suit. If you are prepared to give up on that possibility you can play Gazzilli with all the range and shape benefits as after a 1 opening.
2 - forcing, either balanced, with club suit, or any 17+ HCP hand.
2 - natural, 4+ suit, 11-16 HCP. All rebids natural except 2 maximum with diamond fit (typically 5+ support).
2 - 6 card suit, 11 up to bad 15 HCP
2 - normal reverse, 17+ HCP, not shaded.Lebensohl applies, all 3 rebids by responder forcing
2NT - 14-16 HCP, good playing strength, 6 relatively poor hearts, good 4 card minor. Responder bids 3 (pass or correct, guarantees 4 clubs), 3 (long suit, to play unless this is opener's side minor, 3 signoff, 4 to play, 3 (game force, club fit or slam try in hearts), 3NT (game force diamond fit) or 4 (game force, fit for both minor)
3 ,3 - good 55 or better hand 14-16 HCP in working values, possibly light in high cards if 56 or rarely 65 in the suits. Rebids as after 1 opening and jump rebid in a minor.
3 - 14-16 HCP with good but not solid suit, 7 playing tricks, responder will need about 3 cover cards to raise, a near maximum forcing 1nt to rebid 3NT
3 - about 8 playing tricks with solid hearts, no spade stopper, responder bids 3NT with solid stopper (ace, QJx or similar) else 4 or cue bid. Opener will either have the minors stopped, or at worst three card length, but could be void in spades.
3NT - similar to 3 rebid but with a spade stopper, responder is expected to provide some values in the minors if he passes
4 , 4 - 8+ tricks, long hearts, void in bid suit
2- weak preference, usually less than 8 HCP. With a balanced hand, opener will need at least a very good 16 to continue with 2NT. Continuations of 2 or 3 are help suit game tries with 3 card length, club length undefined. A rebid of 3 shows 5 or possibly 6 clubs and is not forward going.
2 - artificial, 5+ diamonds, 4+ clubs, mild invite at best, opener usually rebids 3 with 5+ length, 3 with 3+ length. He may also rebid 2NT or 3NT with double spade stoppers in balanced hands. Over 2NT responder can correct to 3 with 5-5 in minors, or 3 with 64
2NT - artificial, invite with 6 diamonds, about 8-10 HCP. Opener will need a fitting diamond at least or max points to accept, otherwise usually corrects to 3
2 - relay, 8+ HCP, not suitable for 2 or 2nt rebids - Opener rebids
a) 2 - 11-16 HCP, balanced or with 4+ clubs. Responder may then continue with 2NT (10-11) invite or 2 (choice of part score with 5+ clubs, opener will bid 2NT (1 or 2 clubs) or 3 (3+ clubs). Higher rebids shows 14-16 with usually 4 clubs, inviting 5 contract
b) 2 - 17+ HCP, 54 shape, responders 2nt is relay, opener rebids his 4 card minor. This bid establishes a force to game or 4 of the minor
c) 2NT and 3NT - balanced 15-17 or 18-19 respectively
d) 3 , 3 - 55 or longer, 17+ HCP, game forcing
e)3 - game force, 6+ hearts
f)3 - game force, 0544 shape
It is possible to play the Gazzilli structure after 1-1 and 1 -1nt also, but at present I don't think there is any need for an artificial structure. After 1 -1 , openers 1nt rebid covers hands of 12-16 (or bad 17) HCP. 2 way new minor is adequate to cover responder's rebids.
After 1 -P-1NT- Double, I believe Gazzilli should not apply. Opener can always redouble to show a strong 17+ hand in place of rebidding 2 . You might however wish to retain the limited 55 jumps and the limited artificial 64 2NT rebid. A rebid of 2 however should show at least 4 clubs.
If the opponents double the Gazzilli 2 rebid (presumably showing clubs), responders pass should show 5+ clubs, 2 should be non forcing with 5+ diamonds, and redouble would be used to show 8+ HCP, triggering the normal relay rebids. Opener would have an additional rebid of 2 available showing 5332 shape precisely and fewer than 17 HCP.
If the opponents compete over 2 with an overcall at the two level, double by responder would be takeout with 8+ HCP (or more if the safety level of 2 of openers major had been bypassed. Any rebid by opener over the double is natural, rebids above 3 show 17+ HCP, jumps in new suits are definitely game forcing, when nothing else is clearly forcing opener cue bids the overcallers suit to show a strong hand.
If responders 2 relay is doubled, openers pass shows minimum with 3 diamonds, redouble shows 6+ balanced with 3 diamonds, other rebids retain there normal meaning. If they overcall the relay opener makes his normal rebid if possible, double shows a 16+ balanced hand (convertible), pass is either minimum or a penalty double of the overcall (responder is expected but not required to protect with a double if the bidding is below 3 of opener's major). In any cases where they double higher level relay responses pass by responder is neutral. If they double an artificial relay by responder of 2 , openers pass is neutral, no trump bids confirm good stoppers in suit doubled, redouble shows a stopper in suit doubled but doubt as to the best contract. If they overcall at the three level or higher, openers doubles show strong hands, not penalty but convertible, and are presumed to show a stopper in the suit doubled. Responder may pass or convert to 3NT if he believes that will score better.
Overall Gazzilli handles more hand types more precisely than other methods including those involving a combination of Bart and the Mecksroth adjunct. The rebids showing 64 and 55 hands are inherently aggressive, it is not clear whether some of those hands might be bought at a lower level. Responder needs to exercise caution and not stretch to rebid 3NT over these bids, openers hand is likely to require losing the lead several times before all the tricks are established. In addition, since the defenders knows openers exact shape, the defence may be better. However the Gazzilli approach does allow confident bidding of some low point count slams and games, it seems therefore better suited to imps than matchpoints. The relay auctions do involve a lot of alerting and perhaps allow the defenders opportunities to make lead directing bids or even enter auctions they might not otherwise come into. Going slow on the strong 54 hands however has some real advantages, and the method of sorting out the best minor part score is clearly superior to Bart or standard (using the artificial 2 and 2nt rebids over 2. The only hand types where Bart seems to have the edge are hands where responder has a weak hand with 4 hearts or 5 bad hearts. These hands could end up playing in 2 in Gazzilli where there is a superior 34 or 35 fit in hearts detectable via Bart. Since the convention is virtually unknown in North America, it may also not be allowed in all ACBL events.