[Dinarius]

Yes, I realize that factors such as the auction come into play.

But, for example, I understand that research has been done, using computer simulations, to show that leading from K,x,x,x against 3NT does not pay off in the long run. (I think I read somewhere Tony Forrester does not permit his partner to lead 4th best from K,x,x,x against 3NT)

Has any similar research been done regarding leading from A,x or A,x,x or A,x,x,x, etc. against slams?

Thanks.

D.

Ps. If you Matchpoint and IMPs strategies differ (I suspect they do) please say so.

Pps. This is food for thought.

[NickRW]

I wouldn't argue with Robson. Not because of who he is, but because he is right.

If you want evidence Bird and Anthias (spelling?) wrote a book entirely based on simulations that said the same.

[GrahamJson]

The conclusion of B&A was that an unsupported ace was the lead least likely to defeat a small slam but was also the lead most likely to prevent an overtrick. Hence, other things being equal, it was generally a poor lead at imps but a good lead at MPs.

I should add that these conclusions did not apply to every hand but were dependent upon the exact suit holdings.

[LBengtsson]

if ace wins then need only one more trick and can look at dummy. that helping

[gordontd]

LBengtsson, on 2018-January-14, 04:48, said:

if ace wins then need only one more trick and can look at dummy. that helping

If that one more trick needs developing, you've blown your entry to get at it once you've developed it.

Do you think your opponents are likely to have bid the slam missing two cashing tricks? If so, you may be right to lead your ace to see where your partner's trick is. If not, your argument is much weaker.

[steve2005]

gordontd, on 2018-January-14, 04:56, said:

If that one more trick needs developing, you've blown your entry to get at it once you've developed it.

Do you think your opponents are likely to have bid the slam missing two cashing tricks? If so, you may be right to lead your ace to see where your partner's trick is. If not, your argument is much weaker.

Yes, happens all the time even by experts. Also, AK in one suit or the trick was going to disappear on a pitch.
I'm not saying leading an ace is a great play but has a better chance to work (even if just stopping overtrick at mp) against a slam than most other contracts.

[gordontd]

steve2005, on 2018-January-14, 05:00, said:

Yes, happens all the time even by experts. Also, AK in one suit or the trick was going to disappear on a pitch.
I'm not saying leading an ace is a great play but has a better chance to work (even if just stopping overtrick at mp) against a slam than most other contracts.

My point was not that it does not happen that pairs bid slams with two cashing losers, but that your assessment as to whether it is likely to have happened on the hand in question will affect your decision.

[PhilG007]

Dinarius, on 2018-January-13, 10:06, said:

Yes, I realize that factors such as the auction come into play.

But, for example, I understand that research has been done, using computer simulations, to show that leading from K,x,x,x against 3NT does not pay off in the long run. (I think I read somewhere Tony Forrester does not permit his partner to lead 4th best from K,x,x,x against 3NT)

Has any similar research been done regarding leading from A,x or A,x,x or A,x,x,x, etc. against slams?

Thanks.

D.

Ps. If you Matchpoint and IMPs strategies differ (I suspect they do) please say so.

Pps. This is food for thought.

How many of us here have actually underled an ace against a trump contract? The upshot is,as like as not,it not only resulted in gifting declarer/dummy a singleton king
and thereby allowing a contract to score when it really shouldn't have,but also facing the wrath and outrage from across the table.
The last time I (dared) to do this was when I was a beginner four decades ago and I've never done it since. I'll never forget the 'advice' I got
from my partner who was far better than me at the time "Do NOT give tricks to the unworthy' It's a lesson I've never forgotten.

[gordontd]

PhilG007, on 2018-January-14, 07:02, said:

How many of us here have actually underled an ace against a trump contract? The upshot is,as like as not,it not only resulted in gifting declarer/dummy a singleton king
and thereby allowing a contract to score when it really shouldn't have,but also facing the wrath and outrage from across the table.
The last time I (dared) to do this was when I was a beginner four decades ago and I've never done it since. I'll never forget the 'advice' I got
from my partner who was far better than me at the time "Do NOT give tricks to the unworthy' It's a lesson I've never forgotten.

All very interesting, but not actually to the point.

[JT23456]

I have the Bird & Anthais book - Winning Notrump Leads - p. 22 he says that against a 3NT contract, leading away from a 5 card major headed by a K is a good lead.

[steve2005]

gordontd, on 2018-January-14, 05:09, said:

My point was not that it does not happen that pairs bid slams with two cashing losers, but that your assessment as to whether it is likely to have happened on the hand in question will affect your decision.

Especially at mp, there is a fine line between scientific bidding to find good/best slam and telling opponents what best defense is, especially if you find out you shouldn't be in slam.
So, going to slam without complete information is a valid strategy. There may be 2 cashing tricks or a lead that causes problems.

[Dinarius]

PhilG007, on 2018-January-14, 07:02, said:

How many of us here have actually underled an ace against a trump contract? The upshot is,as like as not,it not only resulted in gifting declarer/dummy a singleton king
and thereby allowing a contract to score when it really shouldn't have,but also facing the wrath and outrage from across the table.
The last time I (dared) to do this was when I was a beginner four decades ago and I've never done it since. I'll never forget the 'advice' I got
from my partner who was far better than me at the time "Do NOT give tricks to the unworthy' It's a lesson I've never forgotten.

Apologies for any lack of clarity on my part - though everyone else appears to have understood me - I was talking about leading Aces against slams, never, ever underleading them.

D.

[Dinarius]

JT23456, on 2018-January-14, 11:17, said:

I have the Bird & Anthais book - Winning Notrump Leads - p. 22 he says that against a 3NT contract, leading away from a 5 card major headed by a K is a good lead.

Yes, that may be true.

But, my point was in reference to leading from four to a King (i.e. K,x,x,x) not five.

D.

[gordontd]

steve2005, on 2018-January-14, 12:13, said:

Especially at mp, there is a fine line between scientific bidding to find good/best slam and telling opponents what best defense is, especially if you find out you shouldn't be in slam.
So, going to slam without complete information is a valid strategy. There may be 2 cashing tricks or a lead that causes problems.

I have the impression that, nowadays, while the tendency is to blast games all the time, most experts take a lot more care about slam bidding. Of course if they have blasted to slam it may well influence you to lead an ace - which is as likely to give them the contract as to find partner's cashing trick. Certainly I'm sure I would have made fewer slams if no-one had ever led an ace against them, though I would probably have also made more overtricks.

[steve2005]

Dinarius, on 2018-January-14, 12:30, said:

Apologies for any lack of clarity on my part - though everyone else appears to have understood me - I was talking about leading Aces against slams, never, ever underleading them.

D.

Under leading an Ace in a slam at least has a chance of success

[helene_t]

If you have a void in another side suit, you can underlead your ace if it seems to be the best chance to get partner on lead. For example, if declarer has auto-splintered in the suit of your ace, and dummy then bid slam, it is quite likely that dummy doesn't have wasted values in the suit so partner might have the king. And if partner wins the king he will know that you want a switch.

It can also work to underlead an ace if dummy has KJ since declarer may play the Jack, figuring that you are more likely to underlead a queen than an ace. But the bidding will rarely give you such specific clues.

[PhilG007]

steve2005, on 2018-January-14, 15:18, said:

Under leading an Ace in a slam at least has a chance of success

But equally, there is the risk of going to bed with it.
Better leading it and save your blushes.

[0deary]

Re your "PS" question...

At MPs they get proportionately a bigger advantage in a slam over game than they could have at imps. The killer one is if they are in 6N in an easy slam with most others in eg 6H at MPs

I don't find assessing their actions based on relative rewards easy. If I’m faced with 3 doors, one safe and two lethal but one lethal get little reward and one door gets a big reward then I’ll stick with the safe door

But you might conclude that at imps opponents look solid and I need to “do something” to knock it. But at MPs they might be stretching a bit so a more solid defence might be better

[Tramticket]

0deary, on 2018-January-15, 05:56, said:

Re your "PS" question...

At MPs they get proportionately a bigger advantage in a slam over game than they could have at imps. The killer one is if they are in 6N in an easy slam with most others in eg 6H at MPs

I don't find assessing their actions based on relative rewards easy. If I’m faced with 3 doors, one safe and two lethal but one lethal get little reward and one door gets a big reward then I’ll stick with the safe door

But you might conclude that at imps opponents look solid and I need to “do something” to knock it. But at MPs they might be stretching a bit so a more solid defence might be better

The reason why it frequently best to lead an ace at pairs is to ensure that you don't concede an over-trick - you never get many get match points when you concede an over-trick with a cashing ace!

At IMPs the over-trick will make little or no difference to the IMPs. You will only do well at IMPs if you defeat the contract and leading the ace will rarely assist in setting up the second trick (unless opponents have bid to slam missing two cashing tricks).

[msjennifer]

Well,it depends upon1)who your opponents are 2) the state of the match 3) If one or two outside suits have been bid which you or your partner apparently can not pose any problem for their establishment ,3) whether it is MP or IMP event.4)whether you will establish an extra trick for the declarer ,5) if one will lose a tempo by leading an Ace.In other words one has to be really on the table and no generalisation can be made.It is similar to a condition whether a Trump lead is advisable in a small or grand slam bid by opponents.