Not Too Swift


7 5 3
J 9 8 2
10 8 6
J 8 3
A 9 4 K J 10 6
K 10 7 6 3 A Q 5 4
K 9 4 3 Q 5 2
2 10 5
Q 8 2
------
A J 7 Vulnerability: E-W
A K Q 9 7 6 4 Opening lead: K of diamonds

South West NorthEast
4 Dbl Pass 4
5 Pass Pass Dbl
All pass

N-S picked up 8 (obvious) winners for a minus 500 against vulnerable opponents. Which would seem to indicate a pretty good sac. But there was one problem. Those guys can't make a vulnerable game, and the sacrificing fellows would up with a rather miserable 19% score.
The opening lead was a heart, ruffed in the closed hand, of course. Declarer now casherd three rounds of trump, then led a low diamond toward dummy, a nervous West going up with the K! Well, now. You tell me why declarer took that third round of trump, wouldja? Because he couldn't count? Because he thought he'd start giving them trouble finding discards? I dunno, but it is clear that if West is going to hop up with the K of diamonds, declarer could easily have held his losses to down 2 or minus 300. Which I dare say would've meant a considerably better score, though unfortunately I cannot ascertain that now.
As for the bidding, South had bid his long club suit, to which his partner was indifferent. So why bid the same values again? Oh, but couldn't South have properly started with 5 clubs, given 8 winners not vul? Yes, I would say so. An opening 5 club bid would at least be in the ballpark. But an opening 4 club bid, giving the opponents the 4 level to find their fit and then a 5 club bid is not too swift.
You might note that North offered no help here, and it would've been wise to count him for nothing. So a four club opening followed by a 5 club bid opposite no help from partner is neither fish nor fowl. You neither give the opps some misgivings about entering the auction at the 5 level nor do you keep your commitment to 10 tricks.

:

K J 10 6
A Q 5 4
Q 5 2
10 5
7 5 3 Q 8 2
J 9 8 2 ------
10 8 6 A J 7
J 8 3 A K Q 9 7 6 4
A 9 4
K 10 7 6 3 Vul: N-S
K 9 4 3
2 Opening lead: 3 of clubs

pass

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

EastSouth West North
1 1 Pass 2 *
4 Pass 4 All pass* Alerted

I don't know exactly what that Alert signified, perhaps a heart fit in their system, but in any event, North is expecting another bid from his partner.
And how about the opponents? Can they make 4 hearts? I have rotated the hand to show the declarer in his usual Southly position. Looking at the hand from that vantage point, it should be clear that those guys can't make 4 hearts . . . Even aside from negotiating that queen of spades, declarer should lose one club, one heart on that bad split and the J 9 8 sitting over the K -- and two diamonds.
But it wasn't to be. East won the opening lead, played another club, declarer ruffing with the 10, at which he led a heart to the A, East sluffing the 7 of diamonds. The 7 of diamonds, huh! East has five clubs left and declarer has a sound 9-card trump holding, by which I mean to say there's clearly no way the defense can force him out of his trump and cash a club or two later. So why not a totally useless low club? Is it advanced bridge to recognize that a few guards to an ace or one guard to an A J will give you a bit more flexibility than no guards? In any even, that's what did it.
Declarer now came back to the closed hand with a spade to the nine! Well, this declarer is living well. Can't knock him for that. To be sure, he could play his diamonds wrong (for that situation, i.e., by leading low to the Q). Well, let's see what he does.
Declarer cashed the A of spades, then went low to the K dropping the Q. (Since he's got a certain trump loser, he can fiddle with the side suit. If West ruffs in, declarer can regain the lead and draw his remaining trump.) He now took two more rounds of trump, ending in dummy, and cashed the last spade, discarding a diamond, following that with a low diamond, East going up with the A! And that was the end of the defense that was rewarded with a score under 4%! Oh, that 7 of diamonds. Could it have been worth oh, call it 50 matchpoints? I 'spect so.
Didn't East just give up after foolishly shorting his diamond holding to two. I would say so. If East plays the J instead of the A, declarer still has to make a right guess. Was East dealt a J doubleton or the A J low? Given that the discard of the 7 of diamonds was a cockamamie play to begin with, I can't see that declarer has a clear path if East at least gives him a guess to make by playing the J. Declarer wins, leads low to the Q 5, West playing the 8 and now. . . Oh, you'd know what to do there? Oh, c'mon.
Anyway, there is no way declarer can avoid two diamond losers if declarer has to attack the suit (which he does, since he can only discard the 4th diamond on the long spade). Second hand low shines here . . . only you've got to save the card, that is, the 7 of diamonds,that makes second hand low a devastating play here.