Redouble!


A 3
------
K J 10 9 4 3
Q J 5 4 2
Q 10 9 8 2 K 6 5 4
9 8 A Q J 10 4 3 2
A 7 5 2 6
8 3 9
J 7
K 7 6 5
Q 8
A K 10 7 6 Opening lead: ?

SouthWestNorthEast
2 * Pass 3 4
Dbl Pass 5 Pass
Pass Dbl RedblAll pass
A man after my own heart. Some time back, I discussed how much a redouble can do for you, even when you're slambound. I first took notice on a cold 6 no hand, where one pair saddled itself with a poor score by playing in 5 no doubled, when they had an opportunity for a top with a simple redouble. Surely if they were slambound, they've gotta feel confident of making 5.
Now, I realize that some people either couldn't or wouldn't feel up to working out the scores for 5 no, doubled and redoubled with an overtrick vs. 6 no, but you don't need to figure out the total scores. You only need to work out the difference to make your decision. Let me start with a not-vulnerable (no trump).
If you redouble a 5-level bid (feeling you surely have little slam), you give up the slam bonus, but in return, you get 3 times the trick score (I'm referring to the difference now), plus 170 for an overtrick plus 100 for making a redoubled contract. Well, the trick score for 5 no is 160, so thrice that is 480 and . . well, right there, you know you've got the 500 slam bonus beat. Let's look at it vulnerable: You give up a 750-point bonus, but get in return 480 more in trick score and 370 for the overtrick plus a hundred. Well, 480 and 370 alone look like more than 750, so you'll see that provided you know how to keep score, there really isn't a whole lot of figuring you need do.
Let me try it with a minor: not vul, your trick score would increase by 300, your overtrick by 180 and 100 for the redouble. Clearly over 500. And vulnerable? You get 300 in trick score plus 380 for the overtrick and 100. Not much, but you do come out ahead of the people in slam (undoubleld), gaining 30 points over the slam bonus you give up.
It won't work against grand slam. That's simply too much of a bonus to make up. Let me take 5 no, fr'instance. If there are 13 tricks there, not vul, you're giving up a 1000-point bonus on the redouble, getting in return 480 on trick score and twice 170 on the overtricks plus 100 for 920. Not quite enough. And vulnerable, you're giving up a 1500-point bonus and getting in return 400 more than not vul, for 1320, a significant shortfall.
Further, with the 5-level redouble, you also have a one-trick cushion in the event that only 11 tricks are available. Which is no small consideration if you're a little tentative about the slam in the first place. On the above hand, it is apparent that either a spade or a diamond lead would allow the defense two tricks, while any other lead would allow declarer 12. If the 9 people who bid 6 clubs, 3 made it doubled, 3 made it undoubled and 3 went down. The above pair was nestled at plus 1400 between those who got doubled in six and those who didn't.
This particular declarer was allowed to make six and so didn't need that cushion, but clearly the defense might have found the way to picking up two tricks, in which case the redouble would not have netted as much as those making slam, but by hypothesis, would have saved the pair from a negative score and allowed a pretty good positive score at that.
And of course, if you've got this difference worked out ahead of time, you don't even need to do higher mathematics during the play. If you genuinely feel you've got the tickets for slam and get doubled at the five level, you've got a better opportunity for a top board or a well-above-average board with a redouble than with pushing on, plus a safer contract. But if you feel you've got grand slam, then the redouble wouldn't pay off if you're right. But it would give you a cushion, you know.