There are a lot of classic positions that are pointed out in books and articles thru the years. A top-level player should be able to handle these positions.
This hand came up during the trials for the national team.
6 NT was a normal spot and the lead of a heart was won by the jack. The declarer could count 11 top-tricks, so he needed to make one more and put his eyes on the spade suit.
South did his math and knew that it was a 75 % chance to find west holding either the jack or the king of spades.
Due to this analyze declarer played his queen of spades, when west followed lows the queen ran to the king at east.
A heart came back taken by the ace. Next came the ten of spades and west had to play the jack. South claimed the rest of the tricks making his contract.
So, was there any mistakes you say?
Yes, I say.
South did a perfect calculation deciding to do the double-finesse in spades. The only thing he did not give too much thought was how to play the spades.
–> He should have started with the 10 of spades.
This would have made also if east had all spades. If west showed out at the first-round declarer could ask for the ace of spades and play another spade back thru east when he still had the queen at hand.
Starting with the queen took away this option. Not a big chance, but still a small improvement that might pay next time around!