Trump Promotion #003 – This deal is 3 of 3 (3/3) on the cardplay technique of trump promotion by position. This thread will flow better to start with deals ...
0008 - Avoiding a Trump Promotion A trump promotion is the defensive strategy of creating a trump trick (or tricks) by forcing the premature use of a trump card. One of the cardplay techniques of achieving a trump promotion is to make a trump trick in passing playing behind an opponent who needs to trump.
0009 - Seeing the Trump Promotion A trump promotion typically happens when the defender (short in trumps) is on lead through an opponent and the defender (long in trumps) is playing behind and both are void in the suit being lead. This forces the opponent to prematurely play a high trump to win the tricks allowing for a trump promotion.
This deal (rotated) was played September 6, 2014 / Unit 252 NAP Championship.
West's opening lead is the ♣ 5. After three rounds of clubs (T1-T2 -T3) East considers the lead options for T4 ... what should East consider? how should East continue?
So here is the trump promotion position after 3-tricks have been played.
The lead of a spade by East finesses his own ♠ K (not good), the lead of a diamond could finesse partner (not good), and the lead of a heart is only good if partner has both the ♥ KQ and the bidding does not indicate partner has this much ... so what about the ♣ 9?
From the time bridge players learn to think about defense, we are told it is bad to give declarer a ruff and a sluff, but double dummy (DD) and what should be apparent to East is that the opponents have plenty of tricks, all finesses are working!! So on this deal a ruff and a sluff doesn't mean anything. The lead of the ♣ 9, however, may allow partner (playing behind declarer) to get a trump promotion which looks like the only real opportunity to gain another trick.
And, in fact, the ♣ 9 puts declarer on a guess: 1) trump in hand hoping that trumps are 3-3 (36%) and that an over trump does not give up a trick? 2) guard against a 4-2 split in hearts by trumping in the dummy and hoping the ♥ Kx are in West's hand? DD the right decision is to trump in hand with either the ♥ Q108, but sitting in South's position, what decision would you make?
The point of this deal is that East's lead of the ♣ 9 is a great lead ... it is the only lead that possibly creates another trick via a trump promotion.
BTW The GIB bridge software trumped in dummy's short stack giving West a trump promotion.
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