It is unusual to find as many finesses in a single deal as there are in this one, but that's the way the cards were actually dealt. What's more, the unhappy soul who wound up as declarer tried and lost every one of them, and so finished a trick short of his goal.
He won the opening spade lead with the queen and promptly led the jack of hearts and let it ride, losing to the king. West's spade return was taken by the king, and a heart was led to the ten, eliminating the opposing trumps.
After cashing the ace of spades, declarer led a diamond to the queen. West won with the king and exited with a diamond to South's ace.
By this time, two finesses had met with no success, but declarer was not yet finished. After winning the diamond, he led a club to the queen, losing to East's king. Back came a club, and South took his last shot by finessing the ten. Down one.
There is no question that declarer was extremely unlucky to have failed on four successive finesses. Nevertheless, the fact is that he took one finesse too many, and it cost him the contract.
There was certainly nothing wrong with trying the heart finesse initially, but after it lost, South should not have attempted the diamond finesse. To assure the contract at this point, all he had to do after cashing the ace of hearts and ace of spades was to play the ace and queen of diamonds.
While playing the diamonds in this fashion might have cost him a diamond trick, it guaranteed that the defenders would never score more than three tricks all told. Whichever opponent won the diamond would have to return a club in order to avoid handing South a ruff-and-discard, and regardless of what club was led or who led it, declarer could not lose more than one club trick.