Counting Winners, Counting Losers

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

Counting winners, counting losers. Traditionally, one counts winners in no trump, losers in trump contracts. There is a reason for that, namely that in a trump contract, you might get rid of a loser, shorting a suit you can subsequently ruff, which you can't do in no trump, where you've gotta have winners or you don't have your contract. There's another reason for counting losers, especially in high level contracts, which is that there are going to be fewer of 'em to count. I personally have a strong penchant for counting winners, which will tend to show you how to play the hand at the same time you count. And I would particularly suggest counting winners and losers in a post-mortem analysis, which should add up to 13, and clarify the hand as well as anything.
However, I have nothing against counting losers if that approach to working out a hand leaps to mind as it might well do in the above hand, in part for the reason given above, i.e., that there are fewer of 'em to count. But there is a danger, a common danger, I would say, that declarers commonly fall into, which is to count losers by a shortage in one hand and then by a shortage in another suit in the other hand. And that can lead to disaster.
Here is an illustration of this in spades. On that hand, declarer saw that clubs were solid, a singleton spade in the closed hand opposite the ace, two low diamonds in dummy opposite four low, solid 5-4 trump holding. That means we only have to lose two diamonds, right? Wrong. You lose four diamonds if you don't have any trump left in dummy when you get around to diamonds. In counting losers, you must count out of one hand or the other, and not mix up the shortages.
On hand above, every card in dummy must either be a winner, or played on a winner in the South hand. If you don't have that, then you don't have a grand slam. Or you can look from the other direction and say every card in the closed hand must either be a winner or played on a winner in the North hand. One or the other. Obviously, there are no quick losers here. But if you draw trump and then start out cashing top cards, you're going to wind up at trick 13 with a low heart in one hand, a low diamond in the other and no grand slam. Your winners will be four clubs, two diamonds, a heart and 5 spades, on three spades leads, ruff, ruff. Hence:
I'm going to count out of the dummy. Clubs are solid, diamonds, well, a stiff ace, spades are solid, but we can't afford to be wasteful. We have the ace of hearts and three little. One of them will go on the king of diamonds, which you'll have plenty of access to later in the hand, leaving two small hearts we must take care of. And that can come only from ruffing. So . . .
It's easiest to see if you get a heart opening lead. Take the ace and ruff a heart, and you're half way home. Back to the ace of diamonds, and ruff a heart, cash the Q J of trump, and when you see the 3-2 split, you know you can afford to ruff a diamond high, draw the last trump, sluffing a diamond and claim.
We could count from the closed hand, where we see we'll have two low diamonds to be concerned with now. However, the entries back look more exiguous with the diamond suit blocked and so it doesn't look as appealing. You might do so, however, with a diamond lead. Club to the ace, ruff a diamond, spade to the queen, ruff a diamond (with the king), cash the A of spades, and now you can ruff a heart, draw the last trump and claim. With a heart or spade lead, it looks as though you could still do it, but particularly with the former would I think establishing dummy's cards would be easier to effect.
For the record, two people bid the grand in spades, one making, one not. But of those in 6 spades, a fair number made an overtrick for a score just under 90%, while those who missed the overtrick got under 63%! The person making grand got 100%, of course, so there was a greater disparity between making or not making an overtrick in six than there was between making the same 13 tricks on a little vs grand slam bid!
Well, lemme see what the defeated grand slam bidder did: Spade opening lead as indicated above. He's not dead yet by a long shot, though a heart lead would have made life easier. Win in dummy, ace of hearts, ruff a heart, ace of diamonds, ruff a heart with the jack, cash the queen of spades, ruff a diamond, draw trump and claim.
What did he do? Well, he ran three rounds of spades, that's what he did. There aren't any losers, are there? Well, in fact, yes. There is one. The last trick was the seven of diamonds, won by West's queen. I don't know the declarer, but I'm morally certain he casually figured, well, I don't have any losers. Every suit is solid. But there weren't 13 winners on that line of play.
I often call the hand referred to above my favorite -- not because an inept declarer kicked a score my way, but because it's the most explicit illustration of that penchant for counting shortages in the opposed hands and figuring losers that way. That declarer didn't play out the hand and begin to wonder with a furrowed brow why he was losing more than expected. After trick 1, he spread his hand and claimed eleven winners. Well, he actually said he'd concede 2 diamonds, but that's the same as claiming 11 winners, no? To be sure, counting a shortage of one suit in dummy and shortage of another suit in the closed hand will often work if you're loaded for bear in trump and get an even break, but isn't so likely to work when your trump suit is a modest 8-card fit or you get a bad break on a 9-card or even 10-card fit. You must account for all the cards in one hand or the other.

There were two declarers in 6 clubs, and like the 2 in 7 spades, one made, the other did not. This declarer got a bad trump split, but the same principle applies. And then, he's a trick lower. So he can get by accounting for every card in the closed hand, while mentally allowing that one will be a loser. Now, he doesn't want to ruff hearts in the closed hand, since he'll need those high honors for drawing trump. Which is to say that he only has to ruff one diamond for his contract.
The 7 of hearts opening lead. This declarer also started out drawing trump, but did take the first round with the jack and did stop after three rounds, so he wasn't dead yet. He can still make it, the 6 bid, that is. Now he went to the ace of diamonds, came to the closed hand on a spade to the jack . . . he only has to ruff one diamond with dummy's last trump. But first he cashed the king of diamonds! Whoa! You don't wanna cash that king of diamonds. You've got one more low diamond to take care of and the spades will give you a re-entry to draw the last trump. But diamonds were splitting 4-4 so he wasn't dead yet. However, after cashing the king of diamonds he now cashed his queen of spades! And now he has no way of making the hand. If he ruffs the diamond, he has no re-entry to the closed hand to draw the last trump.
He followed the queen of spades with a spade to the king, ruffed by East, who led a heart, ruffed by declarer's last trump in the closed hand, a diamond was ruffed, the ace of spades cashed, and the last trick was the 10 of hearts to the king. Down one. In six.