Dormer on Deduction

Deductions from the opening lead

The general public has been led to imagine that a bridge expert is capable of performing almost every kind of miracle with a deck of cards, with the possible exception of making the jack of spades leap out and squirt cider in someone’s ear. Needless to say, this is by no means the case. A true expert seldom does anything very dramatic ans as a matter of fact he does not much care how humdrum or ordinary his plays are, just so long as they have the odds going for them.
However, if there is one department of the game where the tall reputation is justified, it is the department of opening leads. A sleuth-like expert declarer can sometimes glean as much information from a cursory glance at the opening lead as Sherlock Holmes could deduce from a faint whiff of Oriental perfume.

♠ Q 8 6
A 10
A 6 4
♣ K 10 5 3 2
♠ J 7 4
K 8
K 8 7
♣ A J 9 6 4
South North
1♣ 3♣
3NT Pass

Let’s say West leads the 2 against 3NT. Declarer has only four ready-made winners outside the club suit, so needs five tricks in clubs.
There is no problem unless clubs are 3-0. If this is the case and declarer can locate the three of them before he begins playing the suit, he will make his contract. If he can’t, he won’t.<.p>
However, there is no need to stare at the ceiling, spin a coin or employ any of the other time-honored devices for resolving such a dilemma. Poor old West has already given the game away, for the 2 lead has told declarer that East cannot have three clubs.
Against a notrump contract practically all right-thinking bridge players make a practice of leading their fourth-best card from a long broken suit. It is surely reasonable to assume, therefore, that West’s lead of the two means he has no more than four hearts. Since there is no reason why West should have lead from a four-card heart suit if he happened to hold a long suit elsewhere in his hand, it follows that he has no other suit of more than four cards. Therefore, he cannot have a void anywhere in his hand, so if the clubs are 3-0, West must have the three of them. Elementary, my dear Watson.
The opportunity for this type of deduction arises in very many notrump contracts, simply because the players usually lead a long suit against notrump. In most cases, the player on your left is likely to be long in the suit he has led, unless a situation such as in the previous hand exists, it follows that his partner is likely to be long in the remaining suits. For example:

  1.  Dummy
    ♠ K 9 3 2
    ♠ A 10 6 4
  2.  Dummy
    ♠ A 10 3
    ♠ K 9 5 2

Let’s say West leads a spade against your notrump contract. Other things being equal, you should try to develop the diamonds on the assumption that East rather than West is likely to be long in them.
In (1), to give yourself the best chance of three tricks, you should first finesse the nine and when you get in later, cash the king on the second round. This play is bound to work unless East has unexpectedly started with a singleton honor.
In (2) you should start by finessing the 10, rather than the nine, because West is more likely to have a doubleton honor than East, and this will fall when the ace is played next.
Now let’s say that West has led a short suit against your notrump contract. In this case you would play the diamonds opposite to the way described, for this time you would suspect West of being long in the suit.
When a defender fails to lead a long suit against the notrump contract, you should always ask yourself why he hasn’t, applying the good old dog-that-didn’t-bark-in-the-night principle we examined in an earlier article. A possible answer may be that his only four card suit has been bid by your side.

♠ J 9 5 4
K 4 3
10 6 3
♣ A 7 2
♠ K Q 8 6
A 8 7
A K 8
♣ Q J 4
South North
1♠ 2♠

Let’s say West leads the ♣8, which East wins with the king. The club is clearly a short-suit lead and you immediately suspect that West’s only long suit may be spades. The one thing that is a certainty is that West cannot have a singleton spade with short clubs, for this would have given him at least one long red suit to lead from.
Accordingly, when you tackle the spades you play the K-Q first, preparing for a finesse against West’s 10 if East shows up with a singleton.
Many inferences arise when a defender makes a lead which couldn’t have looked good to him when he made it. Let’s say you are playing at notrump after bidding hearts, and the queen of diamonds is led from what turns out to be the Q-J-x. West would not have chosen this lead if there were good alternatives, so you may safely deduce that his holdings in spades and clubs are even more unattractive. This may well assist you later in the play to place the missing honors in those suits.
Less clearly marker — but better than nothing — is the clue that arises when a defender chooses a safe lead in one suit when he might equally well have made a safe lead in another suit.

♠ A J 4
A 10 5
J 9 8
♣ A Q 10 8
♠ K 10 6
Q 8 3
A K Q 10
♣ K J 9

You are in 6NT and the opening lead is a club or diamond, neither of which gives anything away. In either case there is a slight inference that West has honors to guard in the major suits. This may sound doubtful, but nevertheless, if West had held nothing of value in spades or heats, he might have led one of those suits instead. Therefore, if you are eventually forced to take the position regarding the location of the spade queen, you should play West for it rather than East.
It was remarked in a previous article that accurate deductions are possible when a defender who has made a bid turns up with a singleton. In the same way, when a singleton suddenly appears in the middle of the play you should always stop and consider what further inferences may now be drawn from the opening lead.

♠ 10 5
10 6 3
Q 10 4 2
♣ A Q J 7
♠ A 9 6 3
K Q 8
A K 7
♣ 8 6 4
South North

West leads the 2 and East wins with the ace. East returns the 9 to your king and you take a finesse in clubs, which wins. However, when you return to your hand with a diamond yo lead a second club, West shows out. What do you deduce from that?
There is no apparent reason why West should have led from a four-card heart suit if he held five cards in any other suit, so you may reasonably assume he has a 4-4-4-1 distribution. Therefore, when you eventually tackle diamonds, if the jack does not fall under the A-K, you should certainly finesse dummy’s 10.
Finally, do you always apply your powers of deduction to such common situations as the following?

♠ 6 4 2
West leads  ♠ Q  East plays the ♠ 9
♠ A 7 5

West leads the ♠Q against your contract of 3NT. When East plays the nine, there is an immediate inference that the spades are 4-3. If they were 5-2, East would have put up his king to avoid blocking the suit.

This deduction is so reliable that, if it suits your purpose, you may safely win the first trick, abandoning the normal hold-up to prevent West from shifting to a possibly more dangerous suit.

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