This deal was (mis)played in the 2024 Team Trials:

Try playing 4 (no opposing bidding) on a low spade lead:

A1085  KJ  AQ874  K7

Q97  A98753  K93  2

You play low from dummy and when East plays low, your 7 wins. Now what?

One possibility is to lead a club right away, hoping the ace is with LHO. If that is your choice, we'll see later how you did. If you decide instead to draw trump, the normal play is low to the jack, but that is not the correct play on the entire deal. From trick one, you know West has the K -- and quite likely the jack as well. If East gets on lead, he can play another spade and set up a trick for the defense. That leaves you in danger of losing a spade, club and two hearts if they split poorly.

If you play hearts, you want to play them in a way so that if you lose to the queen, it is to West. That player can't get at your spades. Eventually, you'll have excellent chances to get rid of that spade loser (on either diamonds or clubs).  Let's look at the Real Deal:

Vul:North Dlr: Both	A1085  KJ  AQ874  K7
KJ3  2  1052  A96543		642  Q1064  J6  QJ108
	Q97  A98753  K93  2

As you can see, a club at trick 2 would work well. Perhaps this is the right play. Since you know West made a risky spade lead, that increases the chances he has the A (otherwise you might have received a club lead). Playing a heart to the jack at trick two was fatal. East wins and continues spades. Now the contract can't make (declarer has to lose 2 trumps and 2 black-suit tricks). Incidentally, one declarer who played a heart to the jack got a reprieve; East played the Q next and the defense didn't get a spade trick.

Playing a heart to the king at trick 2 works well. Now comes the J. Declarer plans to run this to the "safe" West hand.  Whether or not East covers, declarer is home-free.