The Senior Life Master started his class by saying, “Anyone can cash aces and kings. But for success, most contracts require turning low cards into tricks.” He asked his students to look at the North-South hands in this deal. You are in four spades (the SLM continued). West leads the club king. What are your thoughts?
Vulnerable. Both Dealer: South
Opening lead: 
K
After giving them some time to consider the problem, the SLM resumed. You are faced with four losers: two diamonds and two clubs. Similarly, you have nine winners: seven spades, one heart and one club. The only realistic chance is to establish one of dummy’s low hearts as a winner. That requires ruffing three hearts in hand, so you will need four dummy entries. After winning with dummy’s club ace, cash the heart ace (entry one) and ruff a heart high in hand. Return to dummy with a spade to the eight (entry two) and ruff another heart high. Play a spade to dummy’s jack (entry three) and ruff a third heart high.
Finally, enter dummy with another trump (entry four) and cash the established heart seven, discarding a minor-suit loser. Remember that if you must ruff x times to establish a suit, you need x+1 entries: x for the ruffs and the extra one to gain access to the established winner (or winners). And an entry counts only if you can instantly take a ruff. Here, the club ace is not an entry, because you cannot ruff a heart at trick two. And immediately drawing a round of trumps would be fatal: You need all three trumps as dummy entries.