In Each Direction

K 8 7 5
Q 9 7
K 10 4 2
9 8
A 3 2 Q J 6 4
A 6 10 8 5 2
A J 7 3 8 6 5
K 7 6 2 Q J
10 9
K J 4 3
Q 9 Vul: E-W
A 10 5 4 3

NorthEastSouthWest
Pass Pass 1 1 NT
Dbl Pass 2 Pass
Pass Dbl Pass Pass
Redbl Allpass
NorthEastSouthWest
Pass Pass 1 1 NT
Pass 2 Dbl Redbl
Allpass
This hand elicited a redouble in each direction in the two bidding sequences given. And both proved disastrous. Lemme start with the redouble on two heart bid. This was totally ridiculous, no, not from the knowledge that declarer went down one, but from high likelihood that there was nothing to gain and a lot to lose. On this particular hand, no one made game, and the highest score N-S was 400 (which was indeed, the 2 club redoubled pair, given in the second sequence). So a successful doubled contract would have catapulted the pair to a top score. It's not that the redoubler could have known this specific information at the time of decision, but there are a few things he could be expected to know.
Two hearts doubled is better than four hearts if the hand will allow 10 tricks -- significantly better, since the 9th and 10th tricks would be worth 100 points instead of 30. It's even better than four hearts if you only make eight tricks while others are making game (undoubled), since you'd get 50 points for making the doubled contract. And if the hand doesn't allow 10 tricks, then you're obviously even better off in 2 hearts doubled.
It's true that this was an IMP game, not matchpoints, where you can't get better than 100%. So it's true that there could have been some gain on a successful redouble. But it's gotta be minimal compared to what was risked. As it happened, a minus 100, an often tolerable score when the sides are rather evenly matched, was doubled to 200 a not so tolerable a score when only partials are makable.
But the second sequence, by the vulnerable pair carried their score to minus 400 by the redouble, a very expensive decision and the worst score in their direction, as mentioned above. Actually, the decision was really East's in the passing. The redouble by West is perfectly consonant with good bridge, for it's not rare for opponents to stick in a lead-directing double without realizing the danger they're stepping into, though here South had bid clubs and was perhaps telling partner he had better than a 3-card suit. West redoubles to say, partner, let's try this contract if you have any sort of fit. It has happened that the doubled pair has a tolerable & playable club fit and will want to take advantage of the double. But with both very minimal values and only two clubs, it was East's responsibility to run somewhere. Obviously there's no good spot, but they could at least escape a redouble. East's 2 clubs looks like Stayman to me, and East has to proceed somewhere with just 6 hcp's opposite 15-17 and just two clubs, or in other words, with a bare preponderance of the hcp's facing more than likely the opponents' preponderance of the clubs. Further, they must bear in mind that they don't need just a majority of the tricks but 8 to the opps' five, which will be tough going with no pronounced preponderance in either hcp's or the trump suit. So, vulnerable, the redouble shouldn't have been allowed to stand.
Whether they would find one of their 7-card fits or not is secondary. East should have tried. Anyway, here's the scoop on scoring: The redouble of 2 clubs brought that side -8.7 IMP's, while minus 200 would have been -4.93, a rather significant difference. The redouble of 2 hearts, not vul, of course, brought that side -4.73 while minus a 100 would have been -2.30, not so great a difference, of course, but worth noting.