quiddity

He can super-accept with good 3-card support?

Passing at matchpoints does not appeal to me. Even if I expected "to beat the contract slightly more often than not" I wouldn't want to bet the board on it, not when I have an easy diamond bid.

Do you really think the majority of tables will have the same auction? It's possible of course, but all three bids are probably judgment calls. Some people will not open 5♦, some will not double, some will not pull. YMMV but I wouldn't bet on it.

I think double has more to gain at IMPS. At matchpoints: If both 5-level contracts are down then we're already beating the tables playing 5♦. If 5♦ is making then we're probably not beating 5♠-X enough to make up for it; so we're already losing to those tables. If 5♠ is making then double probably costs the entire board (especially if 5♦-X was going for 500).

I'd bid Michaels on the first. The second seems like a guess between pass and double. Not sure why everyone wants to limit-raise with this hand; we'd bid that way with Qxx of spades so I don't see how it "involves partner". It seems to me that if you want to involve partner you bid 4♠ to show the offensive raise and then double to show something outside. I'm just not sure that this hand has enough outside.

or a splinter?

I thought the original double was ok, but I wouldn't sit for 2S-X!

I think it's close. Just because partner can have a 14-count doesn't mean that he's at all likely to have one, and the three little spades are ominous. Say partner has a 9-count with 4 spades. That's a very likely hand for him to hold and he'll probably bid 3S and could easily end up down 2 which would be a disaster. Consider your expectations when you picked this hand up - a balanced 11-12 r/r at matchpoints where the opponents have a diamond fit, what's likely to happen? Sure some of the time we might have a game or we might double them or whatever, but imo what usually happens is the opponents compete to 3D and we sell. Bidding past 3D r/r is no joke!

Do you play serious/non-serious 3NT? If 3H can include nice 14-counts then responder's hand is non-serious.

Who says we have 400 on this hypothetical hand where partner has several small spades? Perhaps we'll have reasonable luck and make 5♣ but wouldn't you prefer to take the money?

It was a club game, they were lols, and you won the board? Why on earth would you do anything other than smile and say "nice defense"? That play probably made their evening; it would really be a dick move to "rip them for cheating". Do you want to be known as someone who has to claw and scrabble and directorize and throw lols under the bus in order to scratch in a club game? edit: I see the OP didn't specify the event so maybe it wasn't a club game after all. In an "important" event, if I thought the score difference would be significant in the final standings or for qualification or something, I guess I could understand calling the director.

You have a 14-count. They are usually on their way to playing 2S. edit: oops, beaten to the punch by the lalldonn edit.

I don't think that's what it says at all. I think it says "this hand is worth a weak two if you can't raise but it's worth more if you can". I'm not commenting on the actual example hand but I do think there are hands which fit this description.

You either misread the auction or misunderstood the 3♠ bid. It does not show a weak notrump.

I think 3♠ is enough with J-high of trumps. East should raise.

Fluffy, do you have an agreement about whether the pass over 3♦-X showed a minimum or extras?

Why did you duck the club on the first hand? It's not obvious to me how that can gain.

I would certainly play the first double as takeout - probably 2 small hearts and 9-10 points or whatever. Playing this as penalty seems bizarre to me.

Don't get too hung up over differences of a point here or there. All of these ranges are going to be fuzzy approximations. Think of it as "around 6-9 or a bad 10".

Wasn't the first suit-preference signal LHO's ♦8 from Q98? I agree the rest of the carding looks like CK on the right though, and with a side-suit ace as an entry LHO doesn't need to signal anything there so it was probably just random/lowest.

Interesting, I thought that bidding here is approximately the same as bidding over a weak 2♦ opening - a jump to 3♠ would show a strong hand with good spades etc. Is that wrong?

Partner had x Axxx AKxxx Kxx. I tried the undiscussed 3H "splinter" and we had an amusing auction to 6D. Spades and trumps broke so all was well; at the other table the opponents opened 2S and played there. We hadn't discussed the meaning of 3H even by an unpassed hand; I'm not sure if that makes the bid more or less egregious here.

I passed and LHO.. passed! Partner had a 12-count with 6 diamonds and passed it out so we missed a game. LHO had a weak 2254. This was mostly my fault; I didn't really look through the defense when we started the match so I had to ask for the printed defense. When I realized I couldn't bid 2H naturally and passed LHO knew what was going on. Possibly partner felt ethically bound to pass as well - does reading through the defense count as UI? Even if there is no UI consideration, how hard should partner strain to keep this auction alive?

North had - KJTx Kxx QJTxxx.

South passed and North had Kxxxxx Axxxx - xx. I guess this should be a 6D bid over 5D, but I wonder what North should do with something like 6403 and the same high cards.