The technique known as "unblocking" has been explored in a few of my articles, but we have yet to examine the most common uses. Unblocking is essentially a means of preserving (or creating) what we classify as "entry cards."

To maintain an open line of communication with our partners, it is often necessary to play a high card to prevent blocking our partner's suit. A block occurs when one of our cards disrupts the continuation of that suit. By failing to unblock the suit, all communications may be severed with our partner since there may be no other entries available. Furthermore, a suit block may enable the opponents to regain control of the hand before ever returning a desirable suit. This concept is really an issue of tempo and timing (these will be explored in a later article).

Consider the following basic types of unblocking situations:

A. B. C. KQJ10 AQJ10 AJ543 A2 K2 KQ2

Let us assume that North has no other entries to his hand. Analyzing these suits independently from the rest of the hand, note that in each case North's powerful long suit becomes obsolete if South fails to unblock his highest card first. For instance, in cases A and B, North/South are restricted to two winners if South plays the deuce on the first trick.

In case C, three rounds of diamonds may clear the entire suit (if the remaining diamonds are distributed evenly among the opponents). However, the 4th and 5th rounds will be useless unless North can retain the lead by South unblocking the suit on the first two rounds. Note that in this case South may have to unblock twice by playing both the king and queen on the first two rounds. The reader may notice that if North holds off on the ace until the third round it matters not what South plays. However, the point of case C is that North is very likely (understandably so) to play the ace on one of the first two rounds. Thus, the responsibility lies with South.

This point is particularly important if spades have already been run. North's holding becomes much like the spade suit once trumps are extinct and thus the suit should be treated as such. All of the principles of leading spades equally apply to any side suit once the opponents are void of trumps.

D. E. AK6542 QJ109 1093 AK2

Note that in case D, North/South have the potential of six heart tricks! (If the remaining hearts are divided evenly.) Thus, it is critical that South jettisons the 10 and 9 so that North can retain the lead. Case E restricts North/South to three tricks instead of four if South fails to unblock his clubs on the first two rounds.

F. G. A10987 AJ109 J2 K2

In the last two cases, we can see the importance of unblocking in the spade suit. South's unblocking lead of the jack of spades in case F serves a two-fold purpose. First, it allows North to run the suit without delay (a delay may allow the opposition a ruff). Second, it allows North/South to finesse against a possible Qxx holding in West's hand. If South had led low instead of unblocking, North must now find an entry to South's hand so that South could lead his remaining spade – a highly unlikely set of events.

This same principle would hold true for South if he held Kx or Qx. For instance, in case G, most players would be fearful of leading the King of spades. Assuming that South is able to place North with strong spades (through use of the count card principle), this lead is a very powerful lead! Even if North's highest spade is a queen, the lead of the king will most likely prove fruitful. Once again, note what will happen in case G if West holds Qxx.

The following hand that I played recently illustrates rather well the severe damage done when a player fails to unblock:

North A 7 3 A 8 7 4 9 6 2 Q 5 2 West K 9 6 J 10 9 3 K Q 3 J 6 4 East Q J 5 4 2 -- A J 8 5 4 10 8 7 South 10 8 K Q 6 5 2 10 7 A K 9 3 The bidding: West North East South 2 2 7(!) 3 West led the J

East's bid of 7 was a situational bid. North/South only needed 50 points for the win thus East realized their only hope was a set.

West opened with the jack of hearts, North covered with the ace and East trumped with the 2. East then led the Q to North's A and North followed with a low heart to try and tap East's spades. East discarded the 7 and South won with the queen and continued with the king on which East discarded another club. South then switched to clubs and East trumped the second round.

Knowing that they needed the rest of the tricks, East then led a low spade to West's king and West returned a spade to East's jack. East then made the proper lead of a low diamond. West won with the queen and led the fatal 3 (instead of the recommended king). At this point, East could finesse against his own partner (which is not advisable) in order to unblock his partner's king on the next round. Consider what reasoning it would take for East to play the jack instead of the ace. He would have to assume that West made the error of not unblocking his king!

Trusting that his partner made the correct play, East's reasoning was that one of the following diamond distributions existed:

Thus, East deduced he must go up with the ace and hope that either South's king dropped or that West held a guarded king. North/South fulfilled their bid from West's club lead on Trick 13.

-- Dustin Stout