In matchpoints, it is often a difficult decision as to whether you should still be trying to set the contract (the ONLY goal in IMPs) or whether the contract is unassailable, and your goal should be to minimize overtricks. Here are a couple of hands from August 22, 2018 at Adventures in Bridge.
Hand #2. East opened 3NT was alerted as “Gambling.” Your partner asked for the specific definition for this pair (because some people promise a solid suit; some do not; some say an outside Ace of King is possible; other say not). The bid was explained as a SOLID minor or either 7 or 8 cards with no outside Ace or King. Your partner passed. Dummy passed, making a joke, about always passing whenever they are non-vulnerable, and you passed holding: ♠J6 ♥J10432 ♦J3 ♣KQ96.
Your partner made the traditional lead against a Gambling 3NT—an Ace. The objective is to hold the lead, look at Dummy, and try to find five tricks for the defenders before Declarer cashes all those minor suit winners. It was the ♥A and Dummy hit with: ♠AQ42 ♥KQ ♦42 ♣J8753. So, count Declarer's tricks. You know that Declarer has 7 or 8 solid diamonds. The ♥K is a eighth or ninth trick and the ♠A is a ninth or tenth trick. You are not going to be able to set this contract! Partner, seeing Dummy, switches to the ♣A, followed by the ♣4. Declarer has played the ♣2, but clearly still has the ten. (Partner would have led the ♣10 if she had ♣104 remaining.) So you win with the Queen. Do you return a heart, hoping to set up your long suit? If you do, you've forgotten the bidding. Take the fourth and last trick for your side with the ♣K, and be happy that Declarer is not getting any overtricks.
Hand #8, West opened 1♠. You passed with ♠86 ♥1087432 ♦K63 ♣82. LHO (East) bid 2♦ (game-forcing). Partner passed. West bid 3♦. You passed and East (LHO) bid 3NT. Your partner thought a bit and led the ♥J. Dummy produced: ♠AK543 ♥A ♦AJ42 ♣1073. At first, you are absolutely delighted because partner has led your long suit, but look at the spots. Your partner's lead canNOT be from ♥KJ10(x) because you are looking at the ten. The Ace is in Dummy. Partner's Jack absolutely denies possession of the Queen. So, you are forced to conclude that Declarer owns both the ♥K AND the ♥Q. Those hearts of yours are not going to be developed any time soon. Furthermore, since hearts were an unbid suit, partner most likely would have led LOW from Jxx of hearts. Partner should have a doubleton heart. You should suspect that Declarer has five diamonds and four hearts. Declarer plays a spade to his Queen and then puts the ♦Q on the table. Your partner plays the seven; a low card is played from Dummy and you win the ♦K.
THINK! Declarer is known to have the ♠Q, the ♦Q and ♥KQ. He must have a club value as well. However, by your count of the hand, Declarer has either one spade and three clubs or two spades and only two clubs. Your partner is marked for a minimum of five clubs on this auction. (Remember, you expect a doubleton heart from her lead. She has four spades if Declarer has two; five spades if Declarer has a singleton Queen. Partner has only one diamond. So, partner has either five or six clubs, yet she did not lead her long suit. What is the only club holding the makes sense for her NOT to lead her best and longest suit? The only holding that makes sense is that partner has the ♣AQxxx(x) or even ♣AQJxx(x) and did not lead a club because she KNEW from the auction that the ♣K had to be on her right, and did not want to give away a club trick that would never come back. Put that the ♣9 on the table. Declarer started with ♣K5, so no matter what card he plays, partner will take the next six clubs tricks to defeat the contract three tricks!