Count from One Hand or T'other

Feb 6 2000
9 4
A K J 2
K 8 7 4 2
9 3
8 6 5 3 J 10 2
10 9 8 7 4
J 9 Q 10 6 5
K J 8 7 4 Q 5 2
A K Q 7
Q 6 5 3
A 3 Contract: 6 spades
A 10 7 Opening lead: 7 of clubs

By and large, with the exception of occasional crossruffs, perhaps, you'll want to count out a hand from one hand or the other -- and account for every card in that hand. It must be a winner, or go on a winner in the other hand or be considered a loser (you can afford). The mischief in counting losers comes from looking at shortages in dummy for one suit, shortages in the closed hand in another. It may work out if you're loaded for bear in trump, but it's not going to do you well when your trump suit is rather modest, such as the 4-4 heart suit above. You might count out from either hand, but you must stick with that hand out to the 13th card.
Lemme start with counting out the hand from the closed hand: Hearts are solid. Diamonds are solid. You're going to need to ruff the fourth round of spades and the third round of clubs, losing the second round, which you can afford. No, it won't help you a lot to sluff a club from dummy's holding on the third round of spades. You still have to ruff two black cards anyway and would only postpone a black-suit loser for later. Indeed, trying to make something of that potential will more than likely hurt you, for it would wipe out some valuable entries.
Hence, on a club opening lead, I'd duck a round. Taking a chance? Actually, there's a still greater chance that must be taken with a third-round ruff low. It must be low or the ruff on the third round of spades will have to be low, and you've got one more spade than you have clubs, and might as well go with the percentage play.
So anyway, you duck a club, take the next round, ruff a club low, two (not three) top spades, ruff a spade, cash your A K of hearts, back with the ace of diamonds, draw the last round of trump and claim.
Can we play it from dummy more easily? Surely a 3-3 diamond split would make the hand a cakewalk for all the marbles. Yes, yes, yes, but 3-3 splits are not the favored split, and you'd do well to avoid banking on against-the-odds lines of play. Still, you might make out for your contract by playing from dummy, thus: win a club lead (or any lead). Ace, king of diamonds, ruff a diamond high, cash three spades, sluffing a club in dummy, go to dummy for three heart leads, lose a diamond to East. You now have the last trump and the last diamond left in dummy.
Either works, as we see, as long as declarer focuses on one hand and counts it out, i.e., counts out a strategy for only one loser. The cards may be sitting wrong for any line you choose. That's a chance you take, and in duplicate, you figure that if your bidding has been sound, you'll have company in that contract getting the same bad breaks. Here the cards weren't unfavorable for either line of play and the contract should have been made.
Here's a declarer who didn't work out the hand to the 13th trick. Lemme see where he went wrong. Opening spade lead, three rounds of hearts. Oh-oh. He made his mistake early. Unless diamonds split 3-3, he won't have the winners for his contract. He can ruff only once in each hand now and cannot make the contract on the 4-2 diamonds. Well, he continued with three rounds of diamonds, ruffing the third with the queen, two more rounds of spades, sluffing a club, the 7 of spades, losing to the 8, declarer then sluffing a diamond. A club to the ace, ruff a club, and the last trick was the 8 of diamonds to the queen. Down one.
Another declarer got a diamond opening lead and then proceeded to three trump leads, the same as the above declarer. Curiously, this declarer sluffed a diamond on the third round of spades, which doesn't matter here a whole lot, but had the suit split 3-3, that diamond would have been a winner and the sluff would have inhibited picking up the 13th trick. He now ruffed the 7 of spades, lost a club to the jack, won the diamond return, lost another club and won the last two tricks with the ace of clubs and queen of hearts.
Another got a spade opening lead and also took three quick heart leads. But this one at least went after a ray of hope, which was to cash the top diamonds and ruff a diamond. When West sluffed off, he must have seen that he had little hope. Two more spade leads, sluffing a club, ace of clubs, ruff the 7 of spades and now the last two tricks went to East.
Plan ahead!