Incredible

K Q J 7 4 2
J 10 3
8
A K J
8 A 10 9 6 5 3
K Q 9 5 4 2
A J 10 7 2 6 5
9 8 6 2 10 7
------
A 8 7 6
K Q 9 4 3
Q 5 4 3 Vul: Both

WestNorthEastSouth
1
Pass 1 Pass 2
Pass 3 Pass 3 NT
Pass 4 Pass 4
Pass 5 NT Pass 6
All pass

This was a misfit to end all misfits. Six spades sitting over six spades, five diamonds over 5 diamonds. Yow! The contracts ranged from one spade, where the opening diamond bidder didn't think enough of his hand to respond to a forcing bid by an unpassed partner (rattled by the prospect of a misfit?) -- thereby gaining a positive score, at least -- to the above six diamonds, where the diamond bidder thought just a bit too much of a 5-card suit without a hint of a fit coming from his partner. It wasn't the worst score, since it wasn't doubled. One person in 5 diamonds was. It was merely the worst bid.
Well, let's sort the hand out to see where the bidding began to go awry. First, one wonders why South didn't bid his club suit on his second opportunity and a 5-4 holding. A bid of two hearts would be a reverse, which he isn't strong enough for and can dismiss if his partner doesn't bid the suit. But why couldn't his partner have 5 spades and 5 clubs on that bidding? Or just 4 clubs? A fit is so valuable that you want to explore any avenue toward finding one (if your hand warrants a bid). That doubtless wouldn't have changed North's rebid with a near self-supporting spade suit (but not very near on this hand, to be sure), and I don't blame South for the 3 no rebid. It ain't pretty, and if declarer wouldn't have any marked line for 9 tricks, neither would the defense for five!
So here's where the bidding went awry. What's 4 clubs? Gerber? I suspect it is, with 4 hearts the correct answer if so. But who's thinking of slam in the face of such a misfit? You'd do well to find a positive score at this point. And beyond that, what's 5 no? Grand Slam Force? No, that couldn't be right, could it?
North has a good but not spectacular hand opposite an opening bid, and just as you would pump up your trick-taking potential on a super fit, so must you subtract a little on an apparent misfit. So thoughts of slam are completely out of line right there. Indeed, I've always called 17 points opposite a minimum opener a sucker's slam, and he only has 15. To be sure, a spade fit opposite that holding, especially if his partner showed a singleton heart would make any red-blooded player think of slam. But here slam is totally unrealistic on minimum hands and no fit.
I don't blame North for the jump rebid in spades. He has a powerful hand opposite an opening bid and it would only take a couple of low spades in South's hand to make that the desired trump suit. But it looks as though North should have been recognizing the misfit by his partner's 3 no bid, not to mention a hcp count solidly in the game (26 hcp) range and nowhere near slam. If South can't support spades on a jump rebid, he certainly shouldn't have more than a singleton if that many. North should pass three no and lay down dummy meekly.
What were the results? Well, the scores (all for N-S) ranged from minus 1100 for 4 spades doubled to plus 950 for 3 no doubled with an overtrick. How about that? But I'll just give one statistic for scores in the middle: Eleven people were down in 3 no to 19 who made it (counting the top score). Not too bad a chance when there are, after all, 26 hcp's between the hands. But that should also have been a warning against going beyond three no. Nine tricks has to be about your limit on 26 hcp's when there is no fit.