Your contract is 6NT, and lefty leads the ♠9.
You have 11 sure winners: Four spades, two hearts, three diamonds and two

What are your options for a twelfth trick?
Where do you win the first trick? On the dummy or in your hand?
Which option do you try first?
Do you have a third option?

Do well and you’re ready to go. Liquidate every one of your assets and start day
trading immediately!

You have three chances to score your slam:
1) Cash the high diamonds, hoping the J drops.
2) Finesse the ♣J, hoping East has the ♣Q.
3) Lead a low heart from the dummy, promoting South’s J into a winner
when East has the Q.

What’s the order you try them in?

Test yourself before reading the answer below.

So, are you fit for the options market?

Try the last option first. Win the opening lead on dummy and play a low
heart toward the Jack. If East rises with the Q, your Jack promotes into a
winner. If East plays low, your Jack wins immediately. If the Jack loses to the
Queen, try the diamonds next. The club finesse will be your last resort if the first
two options fail.

You may have planned to try the diamonds first, or even the club finesse.
But if both choices fail to pan out, you will be unable to try the indirect heart

You have an almost certain loser in hearts even when the opponent’s Q is
in the right place for you. If you’ve already lost a trick in clubs, or set up a trick for
their J, then playing hearts is certain to result in defeat. You do not have a sure
loser in diamonds or spades. Thus, if you try for hearts first, you can play on
diamonds next, and as a last resort, clubs. You get to test all three of your options
instead of only two.

As a general rule, when you have multiple options, and one requires you to
lose a trick, play the suit with the sure loser first.

Of course, that assumes you can afford to lose the lead.