Devil's Coup-like

 

There is no way for South to show his singleton ♠ in NS's system. Hence, South can only make a mild slam try by cue-biding once and stop in 4♥. Then, North is glad to accept the partner’s slam try of course with maximum and all useful high cards. Well, he does not know ♠K is far less useful than ♦Q or ♣Q or even ♣J. 😓

Anyway, NS reached the poor 6♥ with all AKs but it is likely to be with only about 23%, ♥Q onside & ♥3-2 & ♣3-2.

Is there any better line? 🧐

South tries to cash his AKs and hopes to read something. The sequence of play is ♠A, ♦A, ♦K, ♦ ruff, ♠K, ♠ ruff, ♣K, ♣A. Now is the time to make a decision.

 

EW use old-fashioned signals. High to encourage or even. West followed ♠Q-2-3, ♦3-9-J, ♣2-J and East followed ♠6-5-9、♦4-5-6、♣6-T.

It may still have time to play ♥Q onside & ♥3-2. Is there any reason to play ♦T? Don’t say just because it’s cool! 😎

The analysis of play:

Line A: Finesse ♥Q.

Line B: Ruff ♦T and play ♣.

●　　If both ♦Q and ♣Q are in East

Devil’s Coup-like will be successful. Playing ♦T, no matter West ruffs or not, the declarer can (over-)ruff in the dummy, and play ♣. EW will be thrown in to give up the trump trick.

When East has ♥Qxx/QT/Qx, the line B wins. When East has ♥Txx/xxx/Tx/xx, both line A & B can be successful. When East has ♥QTx, both line A & B will fail, but line B can win if West falls asleep and fails to ruff his partner’s ♣Q to save him to be thrown in.

●　　If ♦Q is in East & ♣Q is in West

♥Q is necessary to be in West also. Line A & B is almost the same.

●　　If ♦Q is in West

Line B almost fails. 6♥ can be made only when East holds luckily ♥54.

Therefore, the key point is: Who has the last ♦Q & ♣Q?

 

The analysis of card-reading:

Even if the opponents may not follow the signals honestly, it can be used as a reference.

♠: East followed ♠6-5-9. ♠6-5 high-low is likely to be an encouragement. It may mean he has ♠T. In addition, if he has ♠7, he may follow from low to high and show ♠7 instead ♠9 on the 3^rd round of ♠. Hence, ♠7 is likely to be in West and the distribution is likely to be ♠QJ732 – ♠T965.

♦: West followed ♦3-9-J. According to the Principle of Restricted Choice, West may randomly follow ♦Q or ♦J from ♦QJ93. Also, if the above inference about ♠ is true, leading from ♦QJ93 instead of ♠QJ7xx is much more reasonable. Hence, ♦Q is likely to be in East.

♣: West followed ♣J2. Similarly, according to the Principle of Restricted Choice, West may randomly follow ♣Q or J from ♣QJ2. Hence, ♣Q is likely to be in East.

In conclusion, South has decided to play ♦T and is happy to see West hesitated. 

This is the first time in my life worth celebrating to complete the Devil's Coup-like! 🥳 The probability of 6♥ must be increased from 23% to about 40%(?).

PS1. The Devil's Coup is a play that prevents the defense from taking an apparently natural trump trick - often called "the disappearing trump trick." While the trump Q can be dropped, it can be just called “Devil’s Coup-like.”

PS2. Such a beautiful coup usually starts with being in a dreadful contract. 😏