These two hands are from Adventures in Bridge, September 4, 2018. Budak Barkan loved to make matchpoint penalty doubles and it served him well. He always encouraged me to double more. I still don't double enough, and end up surprised when I make what feels like a “close” double and the opponents go down two or three tricks.
Dummy (North): ♠A10 ♥974 ♦976 ♣QJ972
You (West) hold: ♠98765 ♥K102 ♦A3 ♣K108
Your partner (East) opens 1♦ and South (RHO) overcalls 1♥. You bid 1♠ (promising five) and LHO (North) raises his partner to 2♥. Partner passes. Since you play support doubles, you know that partner has fewer than three spades. South passes. You have 10 HCP and don't know the right action, so you double. This should be a DSIP double: “Do Something Intelligent, Partner.” Partner elects to bid 2♠, which you know, from the auction, is based on a doubleton. South bids 3♥. You double again. You have no desire to bid 3♠ and don't want partner taking any further action. You have two quick tricks, with the additional chance of a diamond ruff, and partner should have two quick tricks for her opening bid.
Although I don't normally lead Aces without Kings, partner opened diamonds and probably has nothing in hearts on this auction, and little in spades, so I led the ♦A, followed by the ♦3 to partner's ♦K. Partner duly cashed the ♦J and ♦Q, the order indicating suit preference for clubs, as I discarded the ♠9 (upside-down attitude—do not like spades). Partner then led a low heart to Declarer's ♠J and my ♠K. I switched to spades and Declarer took the ♠A on Dummy as partner played the ♠Q (from ♠QJ doubleton). Declarer pulled one more round of hearts and successfully ruffed a low spade with the ♥9. However, when he played a club from Dummy, partner rose with the ♠A and put her fifth diamond on the table. This promoted a trump trick for my the ♥10, so the end result was down 3 (vulnerable) for 800 our way.
South (Dummy): ♠75 ♥9732 ♦97654 ♣74
You (East): ♠AJ732 ♥KQJ6 ♦2 ♣1053
Your partner opens 1♦ and RHO (North) bids 3NT. North is a known “wild man,” but that bid should show a long running minor (almost certainly clubs here), and a stopper in partner's diamonds. North probably has a stopper in one of the majors, but does not guarantee stoppers in both majors. You elect to double. Partner is not sure if you meant it as negative or penalty, so she passes. [We've now agreed that a 4♣ bid by East OR West should be asking partner to pick a major. Double should be penalty oriented.]
You lead the ♥K. Partner signals encouragement with the ♥3 (upside-down attitude—low encourages), and continue with the ♥6 to partner's ♥A. Declarer plays the ♥10 on the first round and the ♦J on the second round of hearts. Partner returns the ♥5 and you cash the ♥Q and the ♥J as partner follows to the fourth round with the ♥8. North (Declarer) discarded two clubs on the third and fourth rounds of hearts. Stop and think about the hand!
North is known to have started with only one heart and probably only seven clubs. (A singleton club in partner's hand is more likely than a void.) Point 1: North has discarded good clubs! Why would he do that? He must be guarding something in the other suits. He almost certainly has the ♠Kx and the ♦K10 of diamonds remaining. If he had Aces, he could discard low cards in the pointed suits and would not have to give up any good clubs. Point 2: Think about partner's hand. She opened the bidding and has shown only the ♥A. She cannot have anything in the club suit, so where are the rest of her HCPs? She must have the ♦A and the ♦Q. That is still only 10 HCP. So, partner must have the ♠Q. Point 3: When partner took her the ♥A, Declarer showed out, so she could have returned EITHER of her remaining hearts to your Queen and Jack. She returned the ♥5—suit preference for the lower suit—diamonds, rather than the ♥8 which would have been suit preference for spades—the higher suit. So, lead your singleton diamond to partner's Ace. She will play the ♠8 back to start unblocking from ♠Q984 or ♠Q964 just in case you have five spades. You will take your ♠J. Declarer's ♠K will fall under your ♠A, as partner unblocks the ♠9. You can lead the ♠2 to partner's ♠Q. She will return the ♠4 to your ♠7 and you cash your ♠3. You have now taken four heart tricks, five spade tricks, and one diamond trick for down six doubled (1400)—more than making up for missing your spade slam.