[Stephen Tu]

You are defending some level of NT, partner leads low in a suit (presumed 4th best), Jxx comes down in dummy. You have K9x. Declarer plays low from dummy
So the suit could be:

---

or

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playing the 9 is kind of a disaster here.
OTOH, the suit could be:

---

or

---

where you have to play the 9.

Now from the latter holdings, declarer is kind of supposed to play the J hoping for underlead from KQxx, or is he??

So what is your general strategy here with K9x? Different depending on field strength?


As declarer is it better to hope for the KQxx underlead or a misdefense from H9x?
Do you do defend differently with Q9x based on partner supposed to be leading A from AKxx(x) holdings with some frequency?

[AL78]

It might depend on the bidding to an extent, but without any other information, you are pretty much on a guess. I get these problems regularly, there are two possible ways to proceed and each one requires a particular feasible layout, get it wrong and blow a trick or three.

Recently my partner led the three of spades against a 1NT contract, dummy came down with ♠J72. I held ♠AQ6. Spades look to be 4-3-3-3 around the table, so if partner has led from the king I should go up with the ace and fire the queen and the small one back. What happened was declarer won my queen with the king which set up dummy's jack. Partner had led from ♠T943. My play in the spade suit resulted in 1NT+2 and a 6% board. The correct answer is to switch to ♦QJT when in with the ace as partner held ♦K865.

[Stephen Tu]

 AL78, on 2020-January-06, 04:56, said:

Recently my partner led the three of spades against a 1NT contract, dummy came down with ♠J72. I held ♠AQ6. Spades look to be 4-3-3-3 around the table, so if partner has led from the king I should go up with the ace and fire the queen and the small one back. What happened was declarer won my queen with the king which set up dummy's jack. Partner had led from ♠T943. My play in the spade suit resulted in 1NT+2 and a 6% board. The correct answer is to switch to ♦QJT when in with the ace as partner held ♦K865.

Your combo is quite different though. There playing the Q is right; if partner has the K it will hold and you know the position as will partner. If partner had the T you lose to the K, but then at least the declarer does not get the J as well, and declarer was already entitled to the K. Suit may become frozen.

Also switching to diamonds is also going to be attractive regardless because you are defending 1nt only and establishing spades is not going to be enough when partner has only 4 of them.