Most of the times when opening lead is out and the declarer is able to see dummy cards, his initial count of winning tricks is short of target. Now he must employ certain creative maneuvers to get the missing tricks. The most important method to achieve his goal is termed as SUIT PROMOTION.

Important point to be noted is that suit promotion is highly dependent on card distribution of opponents and hence it is a probabilistic play with the hope that it will succeed (Although, It may fail many times).

Suit promotion requires certain tricks to be lost strategically. It may sound funny, but that’s where creativity comes into play. Therefore, this action should be initiated early in play as stoppers in various suits are used to get back control with the declarer.

Let’s try with example:

Partnership has 8 cards of a suit and also top 2 of the 3 tricks

	!s	!h	!d	!c
Dummy	6 5 3	K 8	7 6 4	K T 5 4 3
Declarer	A 9 4	A Q	K Q J 3 2	A 8 2

Notice we can count only 5 sure tricks. So we are short by 4 tricks.

But !d and !c suits have 8 cards each in partnership. that means opponents have 5 cards distributed between them in each suit. Statistically, there is 68% chance for each of these two suits to have a 3-2 distribution between two hidden opponent sides.

Let’s assume that the opening lead is 3!h. Declarer wins the trick by moving Q!h and takes control to initiate suit promotion via following steps:

• Lead K!d and hope that distribution of !d in opponents is 3-2/2-3. One of the opponent will win this trick by moving A!d.
• Opponent now will lead for next trick and declarer will have to win back the control using stoppers in other suits. e.g. 7!s can be won with A!s.
• Next two tricks in !d i.e. Q and J are winners. Therefore, with favorable distribution (3-2/2-3), all the diamonds in opponents suit will finish.
• Cheers! 3!d and 2!d become winners in declarer’s hand. He now has 9 tricks in bag.

Note : Even when opponents duck the first round with a smaller card. Ace will have to come out in the next two rounds.

With 8 cards and top 2 of 3 tricks, this suit promotion succeeds two out of three times.

Above suit promotion can be used even in 7 card suit. But you must have top two tricks i.e. AK in partnership. Win one trick first with King then lose one trick with a smaller card and take control again with Ace. Here, the distribution of opponent cards has to be 3-3. Statistically, probability of this distribution is only 35%. Hence chances of success here are 1 in 3 times. (with 6 hidden cards of a suit with opposition, probability of distribution 4-2/2-4 is 49%)

Taking this statistical approach to 9 Cards in partnership. Probability of 2-2 distribution in hidden opponent hands is 41%. 1-3 distribution is 50%. Whenever, declarer has 9 trumps, he should expect 3-1 distribution of trump suit cards hidden with opponents, more often than 2-2 distribution. Expect to neutralise 3 opponent trumps with 4 of your own.
Consider all 4 gone in two moves a bonus.

Observing the chart of various hidden opposition splits, one can conclude that:

• Even number of hidden opposition cards 4 or 6 split unevenly to declarer’s disadvantage. What it means is that 2-2/3-3 type equal distribution is less likely.
  • In 4 hidden cards-Probability of 3-1 split is 50%. Whereas 2-2 split is 41%
  • In 6 hidden cards-Probability of 4-2 split is 49%. 3-3 split is just 35%
• Odd number of hidden opposition cards 5 or 7 split favorably more often.
  • In 5 hidden cards 3-2 split is 68%
  • In 7 hidden cards 4-3 split is 62%