Entry Cards -- How They Affect Tempo

One of the most important components of Tempo is putting the right person on lead at the right time. We must keep the lines of transportation open when possible, such as in this example.

East, knowing that North always covers queens, placed South with the ♣K and inserted the ♣A. East followed with the ♣5 to South's ♣K. South swithced to the ♥J to West's ♥A. West, observing the fall of the ♣10 from South on trick 1, switched to diamonds. After cashing the ♦A and ♦K, West continued with the ♦4.

From this position, we see there is only one line of play for North/South to set East/West. North must ruff with the ♠10, lead the top two spades, and finally enter South's hand with the ♠2. Then South can cash his diamond winners while North throws off his heart losers.

How does North correctly deduce this line of play and correctly unblock spades?

Let us examine the previous plays. Since East/West only need one more trick to fulfill their bid, North must recognize the only possibility of a set is if South has diamond or heart winners to discard his losers. North thus realizes he needs an entry to partner's hand after running spades. He quickly deduces that it is unlikely his partner holds the ♥K since he had led the ♥J earlier. Since West covered the ♥J with the ♥A, East's last count trick must be the ♥K. Thus, the most likely candidate for an entry to South's hand is the spade suit. A brilliant deduction by North allowed them the set by keeping the lines of transporation open and making a key unlbocking play to allow the right player to be on lead at the right moment.