The trump return removed an entry to the dummy before South was ready to use it.
He knew that a trump lead would defeat him by removing a vital entry to his hand.
He might have led a spade, which would have, as it happened, removed a major entry from the dummy.
By attacking the spade ace, he was able to remove a vital entry from the closed hand.
This was a spectacular success, for it accidentally removed a vital entry from the dummy.
West needed to lead her club four, removing a vital entry from the closed hand.
But West led the spade queen, removing a crucial entry to the dummy, and she won with the king.
The database never removes an entry, "except in cases of obvious duplication".
West led the heart ace, which was right in a way since it removed a valuable entry from the dummy.
But West made the annoying lead of a diamond, removing a crucial entry prematurely from the closed hand.