Examples of doubling: good and bad

Starting with the bad. This hand was discussed on BridgeWinners. You hold ♠K862 ♥KQ4 QJ963 7 as dealer, all white, IMPs. Playing Precision, you open 1♦ and partner responds 1♥. RHO now doubles and you redouble to show three cards in hearts. LHO bids 2 ♣ and this is passed around to you.

Are you thinking of doubling?  I believe that there are three reasons that you should not double here:

• You have a minimum hand; partner has shown a minimum response (theoretically, you should only respond to 1♦ with 8 hcp but that's very old fashioned so, let's assume partner has at least 6 points). This is not necessarily your hand so making a cooperative double here puts partner under a lot of pressure.
• You have only a singleton club; if partner chooses to pass for penalties, the opponents will be playing at the two-level with an eight-card fit--that's anti-law.
• You have a seven-card heart fit since partner would have bid 2♥ if he had five and there's no reason to suppose that you have an eight-card diamond fit (you might but the way to find out is to bid 2♦ and see if partner lets you play it there).

The bottom line here is that this is the kind of hand that gets cooperative doubles a bad name. At the table, this hand doubled, partner left it in with a 9-count including KQ92 of clubs and the ace, third of spades. The contract made for -180.

OK, now let's go to the good example hand. This occurred in a daytime game today, playing with my favorite partner. Everyone is vulnerable (matchpoints) and LHO, the dealer passes. Kim bids 1♠ and RHO, a good "B" player, overcalls 2♦. Our hand is 875 KJT54 KQ9 J4. Some people might start with 2♥ but, in a competitive auction, I like to show support right away. I therefore bid 2♠. LHO and partner passed and RHO bid 3♦. Now, I doubled. The play was straightforward and we ended up with 500, for all the matchpoints.

So, why is this a penalty double rather than a cooperative (takeout-oriented) double? I explain this in Update on Cooperative Doubles. But, basically, I have made a limited bid (2♠) and partner has nothing extra because she passed. It's impossible that we have sufficient strength for a cooperative double (see the first bullet regarding the bad example above). Therefore, it must be a penalty double.

Note that RHO did nothing too outlandish. He had 16 high card points and a fairly good six-card diamond suit (missing the KQ, obviously, and the ten which his partner had along with two small). He was just unlucky that his partner had only two queens that were not much help.