There were several hands today in which the defenders needed to be leading trump. Remember, when Declarer shows a 2-suited or 3-suited hand, a trump lead is often best. When you see a weak Dummy with a short suit, but not many trumps, leading trumps to prevent a ruff in the short-trump hand is often advisable.
Hands are from Adventures in Bridge, October 26, 2018.
South (Dummy): ♠9843 ♥K ♦74 ♣K109543
West: ♠J7 ♥1084 ♦KQJ92 ♣A86
North (LHO) opens 1♥. Partner passes and South (RHO) bids 1♠. You stick in a lead-directing 2♦ overcall, and North jumps to 3♥ which is passed by all.
Partner leads the ♦3. You play the ♦J and Declarer plays the ♦6. What is going on?
Declarer must have the ♦A. Your partner would not lead away from an Ace at a suit contract on trick one. So, most likely partner has three diamonds to the ♦10 and Declarer started with ♦Axx in diamonds. So, Declarer is hoping to ruff one diamond in Dummy. You can foil that plan by returning a trump at trick two.
If you return a trump at trick two, you beat the contract one trick. If you continue diamonds or switch to the ♠J, hoping for a miracle ♠AQ in partner's hand, Declarer will take nine tricks.
West (Dummy): ♠107 ♥AQ1082 ♦A ♣J10872
South: ♠A53 ♥9743 ♦K1098 ♣64
You are South and your partner opens a very weak (10-12 HCP) NT. East (RHO) bids 2♠, which is alerted as showing spades and a minor. You pass, as does everyone else.
What should you lead? Declarer is showing a two-suited hand. You anticipate a cross-ruff. Even though you might be giving away a trick, you should lead the ♠A and a spade. If you do that, Declarer does not get ANY ruffs in the short-trump hand.
Here is the full deal, rotated now to place declarer in the South seat.
Declarer's best shot after winning the second round of spades is to immediately give up a spade, hoping for a 3-3 break, which works. RHO, upon winning that spade and looking at Dummy can see that the hearts are never going anywhere with his holding, so he leads a diamond to cut down on entries to Dummy.
Declarer can cash the ♥A and discard a losing diamond. Then, she takes the club finesse, and RHO must be very careful to NEVER cover a club honor—which cuts Declarer off from Dummy forever. Declarer will now get only eight tricks: three spades; two red aces; and three club tricks.
If you lead a top-of-nothing heart or a doubleton club, Declarer will have plenty of time to ruff two diamonds in Dummy and take nine tricks.