BRIDGE NOTES: The winning action

The ability to visualize maximum number of tricks in a particular contract as declarer with the least risk of jeopardising the bid contract is the sole criteria applicable for becoming a good player of the pairs game. For this is what the duplicate pairs is all about - your competition against all the other pairs sitting in your position.
Herein the safety plays are often overruled in favour of gaining an early tempo in the game to score extra tricks that would push your overall score to a greater plus when compared with all others who hold the same cards as you. The pairs game is a real test of this comprehension to outwit not only your opponents but all your competitors placed in the same position as you.
Of course, those hands that belong to the opponents who tend to bid as accurately as possible, need to be fought with equal fervour in order to restrict the declarer to the minimum possible. Any slip by the declarer during play can be a big bonus. But the pairs game is mostly fought on the competitive level of part scores where both sides knowing they have a fit in some suit try to outbid and outscore each other in order to grab the contract at the part level that is the key determining factor of either scoping a plus or a minus score for you in that particular case. It is here that the law of total tricks comes handy for the law states that if both sides have a fit in some suit, the rule is not to allow the opponents to play at their level of par. For say, if you and your partner are competing in spade fit as against opponents' heart fit and you adjudge that the opponents trumps are split 5-3 totalling 8, with your side also on that equal footing of 5-3 fit in spades, then in competing, don't let opponents play in 2H for 8 tricks as the number of trumps would equal the number of tricks.
So allowing them to play 2H would give you - 110 whereas as per the law of total trumps total tricks equal total trumps, ie 8 + 8 = 16 trumps, equalling 16 tricks. So if EW are making 8 tricks in hearts, your side as NS would surely make 8 tricks in spades for a 110 + instead of allowing opponents to play 2H for a minus 110.
Therefore, with 16 trumps in totality, never allow opponents to play at the 2 level; with 18 trumps, never allow then to play at 3 level and so on. EW would of course not allow you to play in your par of 2S bid over their 2H and sacrifice in 3H, most likely undoubled for a - 50 (non vul) - 100 (vul) to beat your par contract of + 110. Let us in the light of above, put our illustration to the test and see the wisdom in it that the players can acquire if they seriously know the law of total tricks and the limitations in sets.
We begin by giving you the following hand: KQJ1062/KQ5/43/82. When you open 1S, your LHO overcalls 2D, your partner bids 2S and RHO raises his partner to 3D. It is upto you now. What do you bid? It is tempting to compete to 3S with that massive spade holding. But lets view in the light of the law of Total Tricks. First, how many trumps do you and your partner assure to have? Most likely 3 for partner for with 4, he would have bid 3S. So your side has 9 trumps. The opponents probably have a 5-3 diamond fit, meaning 8, perhaps if we stretch probably 9. So the total no. of trumps is either 17 or 18.
If 17, let us analyse the consequences: if we play the hand in 3 spades our no. of tricks is either 10 - score + 170, then out of 17, their score if they play in 3D would be 7 tricks, 2 down for +100 to your side as against + 170 if you bid 3S+1. Similarly with 9 tricks for you, your score would be + 140 and they will sore 8 tricks in diamonds down 1 giving you + 50 as against + 140. Even if you go one down in 3S, getting - 50 for 8 tricks then they would be scoring 9 tricks in diamonds giving you - 110. So you see from the above in every case you getter better score by bidding 3S.
Suppose you LHO opens bidding with 5C partner doubles, RHO passes and you hold A43, QJ1054, 96382 many would instructively bid 5H if unaware of the law. For the law tells us that partner has a 4 card heart. Total trumps are 9 as against at least 10 clubs of opponents making a total of 19 so if you are making 5H for 450 (11 tricks) they will be scoring only 8 (3 down for + 500 for you). If you go 1 down for - 50 or - 100 (10 tricks). They are going 2 down (9 tricks) for 300 to you. You see the wisdom of knowing the law. Yes, you pass the 5C double for the winning action.