Playing After Dummy


7 2
A 6 5
A Q 10 5
A Q 7 3
Q 9 8 5 4 10 3
K Q 8 9 7 4 2
8 4 J 9 7 6
9 4 2 J 10 6
A K J 6
J 10 3 Contract: 4 NT
K 3 2
K 8 5 Opening lead: 5 of spades

Declarer was given a gift on that opening lead into the A K J of spades, but that wasn't going to be the end of it. Declarer now took three rounds of diamonds, noting the uneven split, then three rounds of clubs, noting this time the even split, leading to his cashing the 13th club as everyone sluffed a low heart.
Now it gets a bit squishy. The hand would then have looked like this:

7
A 6 5
10
------
Q 9 8 3
K Q 9 7 4
------ J
------ ------
A K 6
J 10
------
------

Declarer ducked a heart to West. Back came the 9 of spades. Declarer won with the A and cashed the K of spades, sluffing dummy's 10 of diamonds, while East sluffed another heart. Now declarer went to the A of hearts, picking up the last heart from each of his opponents and so of course the 6 of hearts was good.
Making 6 for a 96% board. Plus 5 would have been 76%. Or, if I look in the opposite direction, holding declarer to plus five brings a not too shabby 24%, while so carelessly allowing that 12th trick brought a devastating 4%!
It's hard to figure out why East, holding a diamond and two hearts, discarding after dummy, also holding a diamond and two hearts, would keep a diamond when that's what declarer discards, and discard a heart, resulting in his having one diamond to dummy's none and one heart to dummy's two! I mean, he could see that he held the 9 7 of hearts back of dummy's A 6 and even if he forgot that diamonds had all been played out, once that 10 was gone, you'd think he'd want to keep that guard to his 9 of hearts. But it wasn't so.
East, you will note has almost the same distribution as dummy. Of course he can't help the fourth round of clubs, but if he discards a heart on that trick, he'll have the exact same distribution as dummy and should have recognized the easy task, at that point, of keeping the same distribution as dummy.