Simple counting would have saved a couple of ladies from booting away this relatively simple hand and roughly 22 IMP's. Especially the one who got two quick spades leads from the opps. Opening lead goes to the J and ace, and back comes another spade, taken by the K. Now spades cannot be splitting worse than 4-2, and if hearts are no worse than 3-1, you've got an assured contract. A diamond goes on the last spade honor and a club goes on the 5th spade (i.e., after the 4th round is ruffed on a 4-2 split, though of course the split is 3-3 here), and you can ruff a club after all trump are out, barring a miserable 4-0 split. (You, of course, cannot dismiss such a split from mind. On the other hand, you don't want to play as if it's there before a simple test by way of one round of trump!)
Hence, take a round of trump, noting that everyone follows. So you continue with another round to dummy, and then a third, since they're splitting 3-1. Cash the Q of spades, sluffing a diamond. Since the suit splits 3-3, you merely continue with a fourth spade, sluffing a club, and claim.
Here's how the ladies got lost: After winning the second spade lead, declarer went to the K of clubs -- you don't need to touch clubs until late in the hand, barring that 4-0 trump split -- and now cashed the A of clubs! Sluffing a spade! A winner on a winner, it would seem. Before trump have been touched. Now there was a ruff of the 9 of clubs, followed by the ruff of the 6 of spades (another winner on a winner, by virtue of the 3-3 spades). Hey, how many winners do you wanna squander on a valuable slam contract? If you squander enough, you're going down! Now she ruffed the J of clubs. Well, she took care of the club suit, alrighty. But what about that low diamond? You can't close your eyes to that loser! But now, though she still has the Q of spades, she cannot be in dummy with all trump out and so had to go down.
The other declarer didn't get the news on spades so early. But she went down in an far more elementary manner. Diamond shift at trick two, taken with the ace. Three rounds of trump. Okay. Next two spade honors, sluffing a diamond. And of course she's on claim -- except that she now went to the K, A of clubs (sluffing a spade on the latter), then ruffed a club with dummy's last trump, and of course, well, she still had a spade left, but no, back came the ruff of the Q of diamonds, and the setting trick was the J of clubs to the Queen.
So while the first sort of shut her eyes to the diamond loser, and paid for it, the second rather shut her eyes to the club loser and paid the same price -- when that magnificent spade suit was not utilized beyond the third round by the second declarer and not beyond the second round by the first declarer! She got exactly one spade winner on the hand. Oh, she took care of that club suit. No losers there. By way of ruffs, she got seven heart winners. Now seven of them, plus two in clubs, plus one in diamonds and one in spades adds up to . . . ah, you got it.