percentage play

[frouu]

[hv=n=saxhkxxdq93caxxxx&s=skqjxhaqtdaj872cj]133|200|IMPS .. 6♦ by south,

lead ♣K[/hv]

 

Need 4 tricks in the trump suit. Best play?

I was kibitzing this hand yesterday, world class player played small to J. Suitplay says lead Q, if covered ride 9.

There was a long discussion among kibitzers, it seemed they couldn't agree whether the choice of line mattered or not.

[Vilgan]

Edit> nm, see below.

 

I don't think suitplay will consider it, but Q is actually better in the given contract because KTxxx onside can still make 6♦ IF RHO only has 2 clubs.

[Siegmund]

Yes, suitplay counts KTxxx in front of the ace as 4 tricks when you hold the 7.

 

If you re-run suitplay on Q93 opposite AJ842, you'll be offered three equally good lines, one of which is leading to the jack at trick 1. Leading to the jack gains against Txx-Kx and loses to xx-KTx.

 

If you have the 98 in the same hand without the 7, or you are missing the 8, there will be one clearly better line that preserves a tenace.

[pretzalz]

I don't think the line matters terribly. Queen first seems better than to the J since leading to the jack forces low to the Queen next which virtually guarantees 1 loser. Every line seems to lose to KTxx offside. Q first also picks up KTxxx onside which low to the J doesn't unless east is 4=3=1=5.

[Finch]

It is usually possible to work these out from scratch. And better for your bridge than just asking suitplay.

 

Let's forget the issue of a possible overtrick, and just worry about not losing two diamond tricks.

 

Any line that involves playing the Q or J on one of them, and cashing the ace on the other of the first two rounds will pick up all 3-2 breaks for one loser. let's call these the 'normal' lines.

 

Let's worry about 4-1 breaks.

Any normal line will pick up singleton honour (K or 10) on our right.

 

We can pick up K10xx onside by starting with low to the jack, and if that holds continuing with low to the queen. That also picks up all 3-2 breaks, and it picks up singleton 10 offside. Starting with running the queen also works in all these cases.

 

We pick up 10xxx onside either by running the queen, then cashing the ace; or by low the jack then cashing the queen, so that's not a layout to worry about.

 

Single dummy we are going to lose to K10xx on our left however we start the suit. If we play low to the jack and king, we can continue low to the 9 in dummy next, but while that picks up 3 small singletons on our right, it loses to three 10x holdings on our right, each of which is more likely (any 3-2 break is more likely than any 4-1 break).

 

So whether we start with low to the jack or with the queen makes no difference for any 3-2 or 4-1 break. All that's left is the 5-0s.

 

Starting with the queen leaves us safe off with 5-0 onside - we can draw four rounds of trumps without losing the lead and then just play winners.

 

However, this is where suitplay doesn't know the full hand.

 

If we start with low to the jack and discard on a single suit basis we now have two trump losers, however that may not be true double dummy. If RHO is e.g. 3=3=5=2 we can continue with three rounds of hearts, ace of clubs and a ruff, and four rounds of spades ruffing high in dummy. RHO only has trumps left now and under-ruffing clearly isn't going to help him (if he does we'll play a club next followed by a diamond to the queen), so he over-ruffs with the king and plays a trump. We run that round to the 9 dummy and are left with A8 in hand over his 10x and can lead a plain card.

 

So we may not be dead if RHO has 5 trumps if we don't start with the queen.

 

What about if LHO has 5 trumps? After a diamond (discard) I don't think we are off yet, but we are definitely worse off if we started with the queen.

 

So I can see some logic for starting with a low one from dummy, even without thinking the hand through completely.

 

What about starting with a low one from hand towards the queen? That gains when LHO has all five but it loses to e.g. singleton king on our right which is more likely.