As usual, count your tricks. You have seven trump tricks in your hand plus the two red aces in dummy for nine. Where will the 10th trick come from?
If you prefer to count losers, which is often easier in a suit contract, you have four: The defense has already scored two club tricks and knocked out your ♦A, exposing two more possible losers in diamonds. You can afford to lose just three tricks, however, so you need to get rid of at least one of the diamond losers. How?
To succeed, you must set up an extra winner in dummy’s long suit, hearts. If the heart suit breaks favorably, you can make an extra trick. Cash the ♥A, therefore, and ruff a low heart in your hand. Cross to the ♠8 and ruff another low heart with a high trump, then cross to the ♠10 and ruff another heart high. If the defenders’ hearts split 4–3, the ♥J is now good. Simply cross to the trump king and cash the good heart, pitching a diamond loser from your hand. The defense will collect just one more diamond trick at the end, but your contract is secure.
An important point to note, however, is that you can’t immediately draw trumps after winning the ♦A at trick three. You need the trump suit as transportation to dummy’s hearts.
This technique is called suit establishment
