[whereagles]

Low seems best, but given it's a 6-carder, top is worth a thought. Definitely a long-sample simulation problem. By the way, it's not certain pard will know to unblock with all holdings, but I guess we can forget that in a 1st approximation.. lol.

The way 3NT was bid might also be of interest. If 3NT was bid confidently, you might need a miracle to beat it and a top lead might just do it. If opps look ashamed with their bids, low might work better since opps overbid and won't run 9 tricks... lol

[Winstonm]

Trying to guess whether dummy will come down with a singleton spade is somewhat of a waste of time - also, the times when it is right to switch will probably be washed out with the times it isn't along with the times it doesn't matter.

What I want to do is defeat this contract when it is an ordinary contract and is beatable - and that means what is best when the suit divides 322. (And even if it is 6124, low may be necessary)

If partner has 3 cards, then 3/7 ths of the time won't he also hold the Q?
It would seem the only time it is right on combination to lead high is when partner has 3 cards not including the Queen. Isn't that 4/7 of the time he holds 3 cards?

The loss of tempo is a consideration, but with AK to hope that partner has a holding nearly as good and and entry and I have to find the right switch seems somewhat of a stretch. (This could be more important in MPs where cherry picking our 3 tricks may be worth all the marbles).

I am not a mathematician, but it seems to me of the critical holding 3-2-2, that only 4/7 of the tiimes that partner starts with 3 is a high card start necessary - in all other 3-2-2 holdings when the contract is beatable, low offers the best chance to beat the contract if leading my suit is right.

And the other consideration is that low offers the best chance of a push, as I believe the majority would lead low from this holding.

[cherdano]

kenrexford, on Oct 23 2006, 11:26 PM, said:

I'd overcall 2♠ and save myself the grief.

Then at least you could be sure that the suit is not 6421 with partner having the singleton, I agree.

[Echognome]

Winstonm, on Oct 24 2006, 12:13 AM, said:

If partner has 3 cards, then 3/7 ths of the time won't he also hold the Q?
It would seem the only time it is right on combination to lead high is when partner has 3 cards not including the Queen. Isn't that 4/7 of the time he holds 3 cards?

This is exactly the point. The least likely holding for partner is 3 cards.

The second point is that partner will hold the Q less than 3/7 of the time he has 3. Why? Because opponents have the majority of the high cards based on their auction. What the actual probabilities are is rather difficult. But I think you are losing a tempo more often than you think.

[kgr]

I did rerun the sample in Jack after 1NT-3NT with W:
AK9875
xxx
xx
xx
For the bidding system I defined SAYC. I suppose that Jack takes this into account when making the samples.
=> 1000 samples:
SA: -344.8
S8: -367.0
SK: -369.8 (still no idea why, maybe unblocking is expected/not expected)
S6,7,9: -392.0
H3: -501.9
In previous sample the bidding system was Berry for beginners. Seems like SAYC is more strict in leading 4th best.
I thought that the samples were analysed Double dummy, but then there would be no difference in leading S8 or other Sx.