Continuing my series on common beginner mistakes, I note, with relish, that there are many players who don't understand the inherent dangers of making weak takeout doubles. This is because they have never suffered from the imposition of the "blue card".
Here's a case in point from a recent STAC game. You are white vs. red, and you deal yourself this collection: ♠Q975 ♥AJ84 ♦965 ♣K4. You have the world's most ordinary hand: 10 hcp and 4432 distribution. You wisely pass and this is followed by two more passes. RHO opens with 1♣ (playing 2/1 with strong notrump). Are you tempted to double? Surely, you have the most perfect hand for it. Both majors, shortness in clubs... But you still only have 10 hcp and your partner wasn't even able to scrape up a third-seat opener to protect you.
You double. LHO redoubles and partner, who must be weak, declines to choose a suit. Opener passes and it's back to you. What do you do? Surely, you must bid 1♥ now. This will be doubled by your RHO and if you are lucky, you will take five tricks for -500 which will be great if they have a vulnerable game. Actually, I think 800 is the more likely penalty.
Still, you decide to pass and the contract is 1♣XX. Your defense isn't perfect, and the very skillful declarer manages to make a meaningless overtrick for 630, despite being in a 3-3 trump fit. It turns out that your partner, the one who declined to take out the redoubled contract, had QJTxx opposite your Kx.
Now, how do you like these substandard takeout doubles?