Discard in hand with short side suit 2

To gain from a ruff-and-discard you must immediately or eventually get an extra ruff in shorter (or equal) trumps. That does not necessarily mean immediately ruffing with shorter trumps. The gain usually comes from discarding from the hand with the shorter side suit.

Here, an immediate ruff in dummy to discard a heart from hand gains nothing. We would be playing a ruff that would eventually come anyway, and we would still have one heart loser. If instead, we discard a heart from dummy – the hand with shorter hearts – and ruff in hand, we eliminate the heart loser. We will eventually be able to ruff all three low hearts from hand in dummy.