🚀 go-pugleaf

#R:vax2:-67600:hp-pcd:30500012:000:2641
hp-pcd!ching    Aug 29 09:22:00 1983

The original problem:
   Seeing all four hands, make seven spades against the best defense.

                      S T932
                      H AQ5
                      D AQ5
                      C AK2
	S --                	  S QJ
        H JT987                   H K432
        D JT987                   D K432
        C QJT                     C 987

		      S AK87654
                      H 6
                      D 6
                      C 6543

While it is easy, there are pitfalls.

This is obviouly a double squeeze: squeeze both West and East.
Take the opening lead on the board whatever it is.  For simplicity,
let's assume the opening lead is Q of C.  Then run four rounds of trumps
ending in hand.

			S --
			H AQ5
			D AQ5
			C AK2
	S --				S --
	H JT9				H K43
	D JT9				D K43
	C JT				C 98
			S 654
			H 6
			D 6
			C 654

Now lead a spade, North discards 2 of C.  West is squeezed.
Case 1:
	If west discard a Club, then east has to guard Club and be forced to
discard a Heart (or a Diamond).  The situation is as the following.
			S --
			H AQ5
			D AQ5
			C K
	S --				S --
	H JT9				H K4
	D JT9				D K43
	C T				C 87
			S 54
			H 6
			D 6
			C 543

Take AH, ruff 5H, enter board with AD.  (If the opening lead was 
Heart/Diamond instead of Club, replace AH/AD with AC.)

			S --
			H Q
			D Q5
			C K
	S --				S --
	H T				H --
	D JT				D K4
	C T				C 87
			S 4
			H --
	 		D --
			C 543

It's time to cash QH, east is squeezed.  If East discards a Club, then play CK,ruff D to enter hand, and all Clubs are good.  If East discards 4D, then ruff
5D to knock out KD, enter board with KC, and cash QD.

Case 2.

	If West discards a Heart (or Diamond), then 

Case 2.1 

	East can discards a Club.  The situation is 

			S --
			H AQ5
			D AQ5
			C K
	S --				S --
	H JT				H K43
	D JT9				D K43
	C JT				C 8
			S 54
			H 6
			D 6
			C 543

AH entering board.  QH toward hand.  

Case 2.1.1

	If East covers with K, ruff it and knock out West's JH on the way.  
AD entering board.  The situation is

			S --
			H 5
			D Q5
			C K
	S --				S --
	H --				H 4
	D JT				D K4
	C JT				C 8
			S 4
			H --
			D --
			C 543

Now cash 5H, and South discards a Club.  West is squeezed.  If West discards
a Club, all South's Club will be good.  If West discards a Diamond, then play
QD.  No matter if East covers it with KD or not, Declarer has an extra trick
on Diamond.

(The following variations are similar to the above example.  They are left
as exercises for the readers (as Knuth always says). )

Case 2.1.2

	East follows with 4H when QH is playes from the board.

Case 2.2
	East choose to discards a Heart or a Diamond.