Source: www.federbridge.it
Sherlock Holmes is known for his logical reasoning, his ability to adopt almost any disguise and his use of forensic science to solve difficult cases. A bridgeplayer that has been around at the highest level for the last 40 years is Swede Anders Morath, who often comes up with conclusions and questions that no one else had thought about, in the best Sherlock Holmes style.
“Detection is, or ought to be, an exact science and should be treated in the same cold and unemotional manner. You have attempted to tinge it with romanticism, which produces much the same effect as if you worked a lovestory… Some facts should be suppressed, or, at least, a just sense of proportion should be observed in treating them. The only point in the case which deserved mention was the curious analytical reasoning from effects to causes, by which I succeeded in unravelling it.” Sherlock Holmes
Have a look at this problem, presented by Moriathy.
Open Team – 6° Round – Match ANNA-BK 33 TROMSO 2015
Dealer: South All Vulnerable
When the four of diamonds was led, declarer rose with the ace of diamonds from dummy, and West played the jack! Declarer then played five rounds of clubs, learning that West had begun with one and East with four. West discarded two diamonds and two hearts, while East threw a spade. Next came four rounds of spades; the third round of that suit showed that West had started with two and East with five, since West discarded another diamond on the third round of the suit. Declarer is now down to the following four card ending when he plays the king of spades.
Declarer plays the king of spades, East follows suit. Now If East holds the ace of hearts, a diamond should be pitched from hand and you simply play a heart to the king to make the contract. If West has the ace of hearts you should discard a heart and throw West in with the king of hearts to make the contract assuming that he has to lead into the diamond tenace. So now my Dear Watson, who has the ace of hearts and why?
The complete hand:
It’s Elementary, says Morath. Why on Earth would East have discarded a spade on the fifth club if he had the ace of hearts, and therefore could have defeated the contract alone by retaining a spade winner in the three card ending? East can work out to discard a heart from QJ8 since declarer’s line of play marks him with 
A, and thus West must hold either 
A or K.
Ingebrigtsen didn’t find that analysis at the table, and instead went one down by playing on diamonds.
At the other table, Dan Bylund, declarer for team Anna, was in Six Clubs. When the jack of diamonds was led (Russinow, according to their convention card), Bylund won, cashed one round of clubs before trying a heart to the king. West now played back a diamond which East could ruff, for a push…
Worth noticing was that Richard Ritmeijer for team Orange Red, who also declared 6NT, found the winning play in their match against Black for a 2 IMP win, when their opponents had bid and made Six Clubs.