One of the most important results of the modern system of leading is that a
player may know when to unblock his partner's suit; that is, to avoid being
left with the winning card of a suit of which his partner holds the
remainder. The disasters that may result from not unblocking are of
frequent occurrence with those players who either do not know the leads, or
are incompetent to grasp the situation. The following is a simple
example:--
Y holds the ace, knave, 3 of clubs, and four losing cards in spades and
hearts. Z (Y's partner) has extracted all the trumps (diamonds), and leads
the king of clubs; A follows suit with the 2, Y plays the 3, B plays the 5.
Z then leads the 4 of clubs; A plays the 9. Z, {213} knowing from his
partner's lead that the latter has the queen of clubs, ought to perceive at
once that, as regards winning the trick, his ace and knave are equal cards;
but that the former may obstruct Y's other clubs, whereas the latter
cannot. If Z mechanically plays his lower card (perhaps being even deluded
by the belief that he is "finessing"!), he has successfully blocked his
partner's suit; because, when he has played out his ace, he must lead
another suit, and his partner, who had king, queen, 10, 8, 4 of clubs, and
two small hearts, can never get in again to make his two remaining clubs.
If Y had won the second round of clubs with his ace, and returned the
knave, Z would have taken the knave with his queen, and would then have won
tricks with his ten and four. Consequently, Y and Z would have won five
tricks in clubs, instead of only three; Y therefore, by not unblocking his
partner's suit, lost two tricks in that one hand.
Another form of not unblocking is the following:--Y leads the knave of
spades, which wins; he then leads the king of the same suit. Z, his
partner, held originally ace, three, and two of that suit. When Y leads the
king after the knave, Z ought to know that his partner led originally from
five spades headed by king, queen, knave. It is therefore Z's duty to play
his ace on his partner's king, and thus unblock his partner's suit. Z now
knows that, as his partner led originally from five spades, and he held
originally three, making eight, a third round of spades must be trumped by
one of the adversaries. Y, if he knows his partner to be a sound player,
will feel certain that his partner holds one more spade; because, had his
partner held ace and only one other spade, he would {214} have played the
ace on the knave, in order to unblock his partner's suit.
To be able to thus aid a partner, the leads must be thoroughly known, so
that from a partner's original lead it may be fairly estimated what other
cards of the suit he holds in his hand, and when, consequently, it is
desirable to unblock his suit.