Another 4S play problem

[paulg]

[hv=d=w&v=e&n=skthq83dat8762ck2&s=saqj63hkj75dk54c9]133|200|Scoring: IMP

West...North..East...South

Pass.....1♦......2♣.......2♠

3♣......Pass...Pass.....3♥

Pass.....3♠.....Pass......4♠

All pass

 

Lead: ♣8[/hv]

 

The lead is won by the ♣J and East continues with the ♣A. What's the best line?

[Dwingo]

I would discard a ♦ on ♣A and if ♣ is continued, will ruff in dummy discarding a ♥ from hand.

[paulg]

I would discard a ♦ on ♣A and if ♣ is continued, will ruff in dummy discarding a ♥ from hand.

I did see things could get complicated if East continued with a small diamond after winning the first two clubs.

 

Now you would need diamonds to play for no loser or hearts 3-3 or the heart ace well positioned.

 

Or you can ruff the ♣A and play for spades 3-3.

 

Clearly discarding is the best line. In practice spades were 4-2, East held four hearts to the ace but diamonds were 2-2 so the contract makes on most lines.

 

p

[temp3600]

Let's call :

line (1) : ruff the ♣A, pull trumps

line (2) : throw a diamond on the ♣A, take the diamond return in hand, pull trumps

 

I'll ignore 5-1 and 6-0 spade breaks, and 4-0 diamond breaks.

 

line (1) wins if spades are 3-3 (duck a diamond), and needs diamonds 2-2 when spades are 4-2.

 

36 + 48*0.4 = around 55%

 

 

line (2) wins when diamonds are 2-2, or hearts 3-3. If diamonds are 3-1, hearts 4-2 but spades were 3-3, it is possible to set up the diamonds, so the ♥A with West in that case is an extra chance.

 

40 + [60]*0.36 + [38]*0.36*0.5 = around 68 %

 

 

So discarding a diamond on the ♣A is clearly better then ruffing it.

[cherdano]

Line (2) has also squeeze chances if RHO has one diamond and ♥Ax. We win his ♦ continuation with the king, pull trump, and when he play a heart to the queen and ace, he can't return a diamond to break up the squeeze against LHO.

 

Arend