Spots in the wrong hand.

What is the contract you'd want your opponents to always be in? I'd say 5NT, although 2NT is a good candidate too. Well, this time we should have been in that 5NT.

Partner held Axx JT J8xx AKxx and my collection was QT AK9xx AKxx Jx. Bidding was quite interesting.
Partner opened in first seat  all NV 1NT, 12-15, may have singleton diamond. RHO bids 2H showing majors. I pass, intending to go for blood. 2S, passed to me and I double for T/O. Now partner surprises me with a 3S call. I'm not really sure what it shows but a maximum and something in spades and I assumed both minors. RHO doubles and I pass cause I don't really know what to bid, maybe 4NT quantitative would be best. Well partner bids 4C and I just decide to jump to 5D, maybe partner can bid a slam with right cards. Well, he doesn't have to as it gets doubled by LHO. I'm tempted to redouble but leave it be.

Bidding:
1NT (2H) P (2S)
P      (P)   X (P)
3S    (X)  P  (P)
4C   (P)   5D (X)
AP

So, how do you declare 5DX after S3 lead?


Axx
JT
J8xx
AKxx


QT
AK9xx
AKxx
Jx

I think you as well as I can pretty much locate the cards immediately.
RHO holds K(J)xx(x) Qxxxx x xx(x), against 5-0 we stand no chance what so ever, so trumps must be 4-1.
Tough thing is that I couldn't make it at the table and I'm yet to see a way to make it.
I let the spade run to king, another I took with the Q, played DA and diamond. Q took a trick and another spade to ace, I discarded a heart. Now I have the tricks but no entries to take them, while I (partner actually) could easily make 5NT with very little effort.

MSS continuations

This is mainly thought out for strong no trump range, such as 14-16 or 15-17. But I don't see any reason it shouldn't work with weaker ones when you know what you do.
This is a cramped auction and even though I could dedicate some more bids for minor hands, I don't think it's worth the cost as they are rather rare and everyone else faces same problems.
So all my minor oriented slam hands start with 2S over 1NT, MSS asking for better minor. 2NT is better D and 3C better clubs. Over both, 3m is a sign-off.
3M instead shows a shortness in that major but it tells nothing else about responder's hand type. He could still hold (13)(54), (12)55 or either long minor. It also isn't necessarily a slam invitational as you might be trying for 3NT in case partner has "waste" opposite your shortness.
3NT is a suggestion to play. It typically means that responder has a shortness in opener's better minor and a bad slam invitation. If as opener you happen to hold something like xxx xxx(x) in minors, you should definitely pull from 3NT. However 3NT could also be bid with a single suited hand without shortness that was slam worthy if opener fitted for his minor.
4C/D then are just single suited slam invites, not promising but not denying a shortness in other minor. How much the bid shows depends a bit on whether partner already showed a good fit for that suit. (Note that "good fit" might be just xxx, so it's not necessarily good)
4H/S These I reserve for 5 key exclusion bids (AKs of minors and major A) Mainly because it's a cool toy to have.
4NT is like stronger 3NT but it always shows shortness in partner's minor. It's quantitative, so not forcing.
5C/D shows a hand with a really long strong minor that was just too good to bid a direct 5m.

After 3M:
Opener's primary interest is to bid 3NT if there is waste opposite shortness. Any solid holding shouldn't be counted as waste obviously but it's a reason to downgrade. AQ isn't too bad holding either, so with it, you should only bid 3NT if you have bad support for minors.
Over 3H your situation is much nicer as you can bid 3S with all sorts of marginal hands. There responder can bid 3NT as nonserious. Over 3S you don't have such a luxury of waiting call before 3NT.
Over 3S when you don't have waste,  I think it's important to let partner know if you fit the other minor too because that might be the partner's real suit. So 4C tells that you don't have too special hand and no good support for the other minor (xxx at most) 4D tells that you have better than Qxx support for both minors but you are quite minimum. 4H tells that you don't have a support for the other minor but you hold a great hand otherwise. 4S then shows a great hand and support for both minors. Over 3H your 4C/D responses show great hands with no wastage respectively and 3S is any non negative.
At this point I think responder should know pretty well about the slam potential, so he can just bid next step as RKC for opener's better suit and second step for the other. If the response was 4S, 4NT is 6 key RKC. (I think it rarely hurts although it's not always optimal)

After 3M - 3NT:
When the responder has enough to go on even opposite the wastage, I think it's important to just clarify the hand type for opener. 4C/D shows the suit. 4H/S are cuebids with two-suiter (rebidding singleton here is just saying that nothing else to bid), 4NT is quantitative with (31)(54), 5m shows 11(65). (Bid the minor you know partner fits)

Couple general rules:
After responder has shown two-suiter, following RKC from either side should be for 6 keys (but not necessarily for 2 queens).
When responder has shown a shortness and one-suited hand, responder's bid in the shortness suit is RKC.

Transfer Walsh and continuations

Setup: 1C natural without 4D or 14-19 balanced.
1D/H transfers to major, accepting shows 3 card minimum or 14-16 bal.
1S rebid is unbalanced hand. 1NT rebid is 17-19 without 4 card support.
2C rebid is 6 cards unless 1435.
2M shows 4 card minimum.
2H is natural reverse.
2S is natural GF jumpshift.
2NT is some 15-17 6+ clubs without 3 card support.
3C 15-17 with 6+ clubs and 3 card support.
3M 15-17 with 4 card support and unbalanced but no 6+ clubs.
3D 15-17 splinter with 6+ clubs.
3oM 15-17 splinter with 6+ clubs
3NT is 7+ solid clubs and short major with sidesuit stoppers.
4C 12-15, (14)17 or (15)16
4D 12-15, (52)06
4M 12-15, (50)26

This leaves 2D as a multipurpose strong bid ala Gazzilli. It handles 17-19 balanced 4 card raise, (16)18+ unbalanced 4 card raises and 18+ club hands. I think it's well over 50% of the time the balanced hand and because often there is need to bid transfers for contract improvement, I'll make 2M rebid NF. So it's like 4-7 pts with just 4 cards that doesn't necessarily want to be in game opposite fit. With 17-18 balanced opener can pass. The first step (2H/2S) shows 8+ points and is GF. Opener's 2NT is the balanced raise, 3C is clubs without fit and others show strong hands in similar fashion as medium hands showed directly.
If responder holds a shapely hand, he can bid something else than the first step. 2NT is some 64, 3m is 55 and 3M is solid 6 cards or semisolid 7+ suit.

Other responses:
1S = 5-7 bal or diamonds (drop dead or inv+)
1NT = 8-10 bal
2C = GF relay that tends to show 5+ clubs (inverted minor) but could be just slammish balanced hand.
2D = Multi, WJS in either major or balanced invite (11-12)
2H = Reverse flannery, 5S, 4+H, 5-9
2S = Reverse flannery, 5S, 4H, 10-12
2NT = Minors, weak or GF
3C/D = Pre-emptive
3M = ? Club splinters are possible but maybe too rare and can be handled via 2C anyways. Maybe showing shortness and 4 cards in other major? Or 4M and 6+ clubs.
3NT = 13-14 bal

Over 1S (and 1NT):
1NT = 14-17 bal/semibal
2C = 5+
2D = Artificial strong, 18/15+
2M = 10-15, 56+
2NT = 18-19 bal
3C = 6+
3x = autosplinter
3NT = solid clubs, game try

1C - 1D - 1H:
1S = Natural 4 cards or GF "relay"
1NT = 5-8 bal
2C = 5+ clubs, NF
2D = 5+ diamonds, NF
2H = 5 hearts, NF but mildly invitational
2S = 5+ hearts, inv+
2NT = 9-11 bal
3C/D = 55+, inv
3H = Strong invitation, 6+H
3S+ = Autosplinter
3NT = 13-15 Bal

1C - 1D - 1H - 1S:
1NT = 14-16 bal without 4S
2C = 6+C, 3H
2D = 14-16 bal with 4S
2H = Good spade raise (4315/4306)
2S = Bad spade raise

Note: with 54+ majors and GF, you can start with canape transfer to hearts first. When the transfer is accepted, you get a cheap GF sequence after 1S and you can handle all other auctions well too except maybe for some problems after 2NT/3C rebid by opener.

1C - 1H - 1S:

1NT = 5-8 bal
2C = 5+ clubs, NF
2D = 5+ diamonds, NF
2H = Artificial GF, 5+S
2S =  5 spades, NF but mildly invitational  
2NT = 9-11 bal
3C/D = 55+, inv
3H = Strong invitation, 55+
3S = Strong invitation, 6+
3NT = 13-15 Bal

Garbage stayman twist

This is something I have made long time ago and played for almost as long with occasional good results.
Idea is simple, just put together stayman and minor suit stayman in a garbage auction. So for auction 1NT - 2C - 2D, your 2H is weak, both majors. Now you might use 2S as either invitational with 5S and 4H or maybe some forcing re-stayman or perhaps as weak sign-off with longer spades. However my idea is for it to be nonforcing MSS.

If you haven't played MSS, it's rather simple: 1NT - 2S: 2NT = better diamonds and 3C = better clubs. Now responder can bid either minor to sign off or bid 3M to show shortness and usually some slam ambitions. In these garbage auctions you never have slam ambitions but it works for the sign-offs.

So after partner opens 1NT and you hold weak hand with spades and a long minor or both minors you start with stayman and if partner delights you with 2S you pass. Over 2D or 2H you bid 2S to say that you have weak hand with 4S and long or both minors. Partner passes with 4 and usually with 3 cards and answers MSS with just 2.
Hand types like 40(54), 41(26), 42(16), 43(06) and 40(36) just found a way to search for 4-4 or 4-3 spade fit before committing to 3 of a minor.

Note that you also lose 1NT - 2C - 2H -2S bid for this purpose. (Whatever it might have been before)
One additional thing to note is that you can bid some marginal invites through this auction if you'd accept an invite for one fit but not for the other. I have also used it with 5044 shape finding 4-4 minor but that is more questionable.

The 9-ball

No, I'm not talking about pool.

This is the wackiest system I have ever come up with and I've had some pretty weird ideas. Actually it was initially an idea of friend of mine but I put it in real use.
You see, there is one common thing in all unbalanced hands. There is minimum of nine cards in combined two suits. (Doesn't include 4441s) We have six different  combinations of suits: minors, majors, reds, blacks, pointed and rounded suits. We can hardly spare six bids for them. (actually we might, but that seems boring) Instead combine two of them under one bid. Mix in a strong pass, fert and weak NT and here are our opening bids.

Pass = 15+ any, could be 13 or could be 16+, whichever way you want to go. 15 seems to keep my openings well enough defined.
1C = Minors or majors or any 3-suited hand. 10-14
1D = Reds or blacks. 10-14
1H = 0-9(11)
1S = Pointed or rounded. 10-14
1NT = 11-14
Your all shapes are handled, so use 2-lvl  bids for whatever you wish. One reasonable alternative is to use constructive single-suiters to take of some burden from the openings. Something like 9-12, 6+
Alternative is to fit in as many pre-empts as possible to take strain from 1H. But 1H is already pre-emptive in itself and it turns easier for opps to penalize it when it's balanced like 90% of time, so I'd rather take the constructive route.

When your hand fits for multiple bids, open at the lowest lvl. This means that 1C is opened a lot and the main reason I wanted to make this a forcing pass. You could use similar openings in a strong club context but losing one step on each of your three commonest openings (excluding NT), it's not so good.
So 1C opening can have AKxxx AKxxx xx x, xx x AKxxx AKxxx or any 7222 for example. It seems the bid tells you nothing, but that is only an illusion. If allowed constructive auction, your relays become super accurate. You can at best get the shape resolved as low as 2H. And when it gets competitive, your opponents often tell you what suits your partner is holding. Only problems ever come from single-suiters and they are always max with those 2 bids, so they shouldn't be too problematic.

Responses are basically that first step is relay (usually inv+), others natural NF or pass/correct bids. I don't recall ever wanting to bid anything but the relay and 1NT so they are maybe bit underused.

This was just a preliminary introduction. I'll probably rework the relay responses I'm using so I'll be back with them. They are otherwise good right now but there is no way to remember them.

Working towards 1NT GF relay

Inspired by the Viking Club precision book I recently bought, I've been trying to get towards 1NT GF relay over major openings. When you have the GF hand, it's simple. Trouble is what you are going to do with all the hands natural systems handle with 1NT. Now that I got my bright idea for 1S-2D (hearts), it's little work to finish the rest of the structure. Viking club went a simple way, 2C included about all the invites and other bids were NF. Not too hard to see how this is rather horrible, now-a-days everyone knows that fit is everything. So at least my heart hands are separated.
My 2C bid will look something like this:
Balanced invites without 3 card support. (also with 5H)
Both minors invites.
5+m, 4H invites
6+ diamond invites.
6+ diamonds GF that doesn't want to relay.
55+ minors GF that doesn't want to relay.
Essentially the bid works as a transfer to diamonds because opener should have some shapely hand to bid something else.

1S - 2C
->
2D = Nothing special (says nothing about strength)
2H = 5+4 majors (may have 55 if really bad)
2S = Good 6+S
2NT = Max 6S4m
3C/3D = 55+
3H = 55+ majors
3S = Max with semisolid spades
3NT = Solid 7+ spades

1S - 2C - 2D
->
2H = 5H, inv. Includes some semibal shapes. 2533, 25(42), 15(43), you can bid these also via 2D, this is the lighter way and more often has bad hearts.
2S = Exactly 2S, usually balanced but could be both minors.
2NT = Both minors, usually short spades.
3C = GF with both minors
3D = 6+D
3H+ natural bids with GF and 6+ diamonds.

Forward to 2H bid:
Weak spade raise.
Invitational 3 card spade raise.
Invitational with clubs.
GF with clubs that doesn't want to relay.
This seems straight forward so I won't bother to write the continuations here.

Leftovers:
Less than invite hands without support including some 6-9 balanced, both minors or 5Hs hands and weak hands with long minor. These hands just have to pass as you have no bid for them. I'm not too worried about that, 15+9 rarely makes games and often opps are there to balance. Those heart hands are a bit scary but they aren't too easy even in natural systems.

Transfers, 2/1

Finally I figured it out! It's a structure I had already made once for 1NT. Retransfers to give you all the possible room.
1S - 2D, transfer showing hearts. I wanted to fit in weak hands with long hearts that just want to play there, single suited and two suited invitational hands. Of course it has to be able to handle them all when GF. In addition I want to be able to show some 6+H, 3S hands that wouldn't want to relay. (For the fear of competition and to get the chance to show choice of games) I know some aim for being able to stop at 2H here with inv opposite minimum opener without much of a fit, but I think that's aiming for rather small target. I'd rather have a way to drop off in 2H with weak hands with hearts.

1S - 2D
->
2H = Nothing special, should happen some 80% of time I guess.
2S = Good long spades with short hearts, doesn't deny or promise extras
My 1S is limited, so everything else shows a fit. You need something to show strong hands in natural so you have less ways to show hearts but that's not much of a problem since I feel I have too much room.
2NT = Heart fit with bad spades and good minor suit cards, suggesting that spade shortness isn't a bad thing.
3C/3D = Shortness
3H = Other max hands with hearts
3S = Some wild shape like 64 or 73 majors with good spades. Not forcing but opposite some KQ of hearts, should definitely be in game.
3NT = This is the one hand that doesn't have fit, it's a gamble with solid 7+ spades and a minor card, usually heart shortness.
4C/D = Void with some freak
4H = 6511 or 7411 I guess...

Now, where the beauty starts.
1S - 2D - 2H
->
2S = Transfer to clubs, inv+ (54+)
2NT = Transfer to diamonds, inv+ (54+)
3C = Transfer to hearts, inv+ (6+, may have 3S)
3D = GF with 6+H, 4D
3H = GF with 6+H, 4C
3S = GF with 6+H, no shortness
3NT = Solid hearts (AKQJxx or AKQ 7th)
4x = 7+ hearts and a void (I use steps but could be natural as well)

Over those transfers, bid the next step with non fitting minimum, show the fit at the minimum lvl with min. Next free bid denies fit and is max, one after that shows heart fit and then you show diamond fit and shortness in steps.
So:
1S - 2D - 2H - 2S
->
2NT = Min, no fit
3C =  Min, at least xxxx in support of clubs
3D = Max, no fit
3H = Min, heart fit
3S = Max, heart fit
3NT = Max, at least xxxx support to clubs, no shortness
4C =  Max, at least xxxx support to clubs, heart shortness
4D = Max, at least xxxx support to clubs, diamond shortness
Over 2NT 3C shows 55 and is NF, 3H shows 64 and is NF. Others are patterning out with GF hand.
Note that over 1S - 2D - 2H - 2NT - 3C, you are bit jammed (Can't get back to 2NT) My suggestion is actually to just show the 1543 as balanced invitation, whatever your way to show that hand. That's how I handle 2533 anyways. Of course you can also just let it die at 2H and hope you didn't miss anything. (No great heart fit opposite, but you may end up in 5-1 fit)

Over 1S - 2D - 2H - 3C
->
3D = Min, suggests spades instead of hearts
3H = Min, typically at least doubleton support
3S = GF with no real heart support
Others fit hearts and show shortness in steps.

That's about it. I think you can easily fill in the blanks. I guess I should go around testing this.