I played this deal in an online game. As South, I held:
♠ 10 6 5 ♥ 10 2 ♦ A 2 ♣ A K 9 8 6 5
My right-hand opponent dealt and opened with a weak 2♦. We were not vulnerable against vulnerable, which helped rationalize my light overcall of 3♣. LHO preempted to 4♦ and we made our way to 6♣. I received a diamond lead, and it was easy:
Not much of a lesson here. I won the ♦A, drew trumps ending in hand (they were 2–1) and led the ♥10. More on my result later.
This deal piqued my interest because I thought it would make a good Real Deal, had the opening lead been a low spade. In fact, here is the problem I pose: How would you play on a low spade lead if you were in 5♣? Or in 6♣? Or in 7♣?
In 7♣, you shouldn’t risk the spade finesse. You need the heart finesse anyway, so win the ♠A, draw trumps and run the ♥10. Your 10 holds (you needed that!); only a really bad layout will doom you at this point.
What would you do on that annoying low spade lead in 6♣? If you win the ♠A and rely on the heart finesse, you will be defeated when the ♥K is wrong. Better is to try the ♠Q at trick one. If it wins, you are home free. If it loses, you can fall back on the heart finesse. That gives you roughly a 75% chance (making when LHO has either major-suit king).
If you underbid to 5♣, you should not finesse the ♠Q at trick one. That is the only way to go down. If RHO has both major-suit kings and LHO has the ♠J, finessing will hold you to 10 tricks. RHO will win the ♠K and return a spade to your 10, LHO’s jack and dummy’s ace. Now, if you take a losing heart finesse, you will go down in five!
The way to assure your contract – and still make overtricks if the lead is from ♠K J – is by playing low from dummy at trick one! Even if RHO wins the jack, he can’t get at dummy’s spades. Given RHO’s opening 2♦ , the spade lead can’t be a singleton. Or, if you want to try for two overtricks, you can win the ♠A at trick one, draw trumps and try the heart finesse. You’ll end up making either five (losing a heart and a spade) or seven.
Let’s review that. On a low spade lead, your strategy in 5♣, 6♣ and 7♣ is to play the ♠4 or ♠A at trick one, the ♠Q at trick one and ♠A at trick one respectively! The teacher and logician in me is easily amused by such things. This was the Real Deal:
As you can see, on the easy diamond lead, I made 12 tricks in 6♣. A spade lead would have defeated my slam. On a spade lead against 5♣, declarer will go down if he plays dummy’s ♠Q at trick one.