sanity check

[Fluffy]

Match points:

♠K84

♥73

♦Q1063

♣8653

 

partner passes, and it goes 1NT-2♣-2♦-3NT

[PhilKing]

There are lots of these in the Bird/Anthias Winning NoTrump Leads book.

 

Heart at match points, spade at imps.

[fromageGB]

always ♥

[billw55]

There are lots of these in the Bird/Anthias Winning NoTrump Leads book.

 

Heart at match points, spade at imps.

Interesting, why should this be so?

[Codo]

Spade at imps. Partner did not open, so he has less then an opening. My best shot for defeating is something like AQJxx in spades and out...(If he has less values in spades, he may hold something outside and an entrance...)

 

Heart at mps. They will usually make and I won't help them to make more tricks then they are supposed to have.

[TWO4BRIDGE]

♥ 7

♥ has the best chance ( in the majors ) to find partner with 5 cards .

From Rule-of-11, he will know I don't have 4 of them when I lead the 7 .

[PhilKing]

Interesting, why should this be so?

 

1. Passive leads tend to rate pretty highly in the simulations. Interestingly, passive leads were particularly good against 3NT - against 1NT we should be more inclined to attack.

 

2. Leads from four card minors are fared very badly in almost all the simulations. What I mean by really badly is that you should not even consider leading a diamond.

 

3. QTxx suits did not fair all that much better than, say, Kxxx.

 

Passive leads are definitely overrated by simulations though - they rely on partner finding the right switch all the time.

[billw55]

1. Passive leads tend to rate pretty highly in the simulations. Interestingly, passive leads were particularly good against 3NT - against 1NT we should be more inclined to attack.

 

2. Leads from four card minors are fared very badly in almost all the simulations. What I mean by really badly is that you should not even consider leading a diamond.

 

3. QTxx suits did not fair all that much better than, say, Kxxx.

 

Passive leads are definitely overrated by simulations though - they rely on partner finding the right switch all the time.

 

I wasn't considering leading a minor. What I meant was, why choose spade at IMPs and heart at matchpoints? I see Codo has offered an explanation, would you add anything to that?

[barmar]

Passive leads are definitely overrated by simulations though - they rely on partner finding the right switch all the time.

If you play against the robots on BBO, you'll find that they lead like this frequently (not surprising, since they choose their defense based on simulations similar to to those used for the book). And since its partner is using the same simulation method, it frequently does find the switch rather than blindly returning the suit.

 

In fact, on the occasions when it makes an attacking lead and declarer ducks holding just Ax, it will sometimes switch instead of continuing, allowing declarer to make unmakable contracts.

[PhilKing]

I wasn't considering leading a minor. What I meant was, why choose spade at IMPs and heart at matchpoints? I see Codo has offered an explanation, would you add anything to that?

 

Not really - Codo has covered it.

 

If I can find the book, I will see if there is a relevant hand that offers more insight.

[mikeh]

I would lead a spade at both forms of scoring, but I understand the idea of a heart at mps and a spade at imps.

 

At imps, we are assuming we can beat this despite partner having limited assets. Our best shot, given that opener has no major, is to hit partner's presumed major length.

 

He needs far more in hearts than he does in spades, because he is entirely on his own in the former suit.

 

Thus AJxxx in spades, especially if dummy hits with Qxx or xxx, is gold, while the same holding in hearts is not only of dubious value but may be damaged by a heart lead: imagine dummy with Q108x and declarer K9.

 

Thus at imps we attack the suit where, if we have guessed correctly, the 'good lead' is most likely to help.

 

At mps, on a power auction, we would often choose to go passive. Indeed, if my majors were Kxx 7xx, I'd lead a heart.

 

I don't think xx is a good lead when a reasonably common layout is that dummy holds 4 and declarer holds 3. That could be the case when I hold 3, of course, but then the suit is 4333 and my lead is less likely to blow a trick.

 

I might also lead a heart at mps if my spades were Qxx and hearts xx. However, even if declarer has spades locked up, my King will still likely score a trick when declarer holds the A, while leading from the Q might blow the entire suit.

[JLOGIC]

I still think a heart is bad at matchpoints. As PhilKing noted, leads like a heart are not only overrated because partner always finds the right shift, but also because declarer is always going to pick up hearts left to his own devices. In real life, we are going to pick off the heart holding a lot which double dummy simulations will not account for. Partner's AJxx or QJxx or Qxxx or Jxxx etc etc were all always going to be picked up.

 

IN THE REAL WORLD, TWO SMALL IS NOT PASSIVE. IN SIMULATIONS IT IS.

 

In real life, partners heart holding would be unlikely to be picked up if he has only 4, because dummy will have the length.

 

If you want to be passive, why not lead a club which is actually passive? It does not have the upside of a heart, but it is unlikely to be picking anything off and partner is unlikely to misdefend later on.

 

To me it is an automatic spade lead at imps and between a club and a spade at MP (I would lead a club). I am happy to just not blow a trick on lead when I'm defending normal contracts at MP. I hope people keep reading David Birds book and failing to understand the limitations of double dummy analysis. Maybe they will just bang down aces or lead from 2 small all day.

[Fluffy]

Sanity Check: Failure

[JLOGIC]

lol

[campboy]

From Rule-of-11, he will know I don't have 4 of them when I lead the 7 .

So that's what the rule of 11 does! I never understood it before.

[Trinidad]

Sanity Check: Failure

But Gonzalo,

 

By now you should know that diamonds are a girl's best friend.

 

;)

 

Rik

[the hog]

Spade at imps. Partner did not open, so he has less then an opening. My best shot for defeating is something like AQJxx in spades and out...(If he has less values in spades, he may hold something outside and an entrance...)

 

Heart at mps. They will usually make and I won't help them to make more tricks then they are supposed to have.

 

Partner cannot have this S holding as he did not open with a weak 2. I would lead a H.

[BunnyGo]

Partner cannot have this S holding as he did not open with a weak 2. I would lead a H.

 

AJxxx

 

would be enough too depending on the position of the other cards.

[rhm]

Interesting, why should this be so?

Because it does not pay at matchpoints to take your best chance of beating them when by doing so the risk of giving them an additional trick is high while the overall chance of beating them remains low.

 

Rainer Herrmann

[fromageGB]

A rhm says. At imps, the cost of an overtrick by leading spades and giving a spade trick away is small, while the gain from being able to set up partner's hand should he also have sufficient in spades, to take the contract off when it would otherwise make, is high. Crudely, to gain a possible 8 IMPs it is worth taking a risk, losing 1 IMP when a 1 in 5 chance does not pay off. Conversely, at MP the attacking play gets you a 20% score.

 

However, this crude arithmetic overlooks the fact that on passive play (heart or club lead) the contract may be going off anyway, and your aggressive spade lead lets them make it.

[billw55]

I admit, I don't see why a spade is so much more likely to give away a trick than a heart - and enough more likely, to make it worth giving up the extra chances to beat the contract. Setting them is also worth some matchpoints, right?

 

Maybe this perception is something that will come with experience.

[fromageGB]

I admit, I don't see why a spade is so much more likely to give away a trick than a heart - and enough more likely, to make it worth giving up the extra chances to beat the contract. Setting them is also worth some matchpoints, right?

 

Maybe this perception is something that will come with experience.

Yes, it is worth something when it works out, the satisfaction of getting a whopping +50 rather than a -400, maybe an absolute top. But not more matchpoints in the long term. Look at it this way, and follow through the arithmetic.

 

Suppose dummy has ♠A65 ♥A654 and declarer has ♠Q32 ♥Q82.

You lead a small spade, and declarer wins 2 tricks in that suit, ie Q then A. In hearts he has 2 trick, as his Q is on top of partner's K. Total 4 tricks.

You lead a heart, and declarer wins only the same 2 tricks in that suit, and when he plays spades, he will win only 1 trick as your K will cover declarer's Q. Total 3 tricks.

Your spade lead has given away a trick.

 

Of course there are many distributions, but you are very likely to lose a trick when declarer has the Q.

 

Now look at matchpoints. Assume there is a 25% chance of the spade lead resulting in +50 when partner has spade values AND you need the tempo of the lead to get those tricks, 25% chance it makes no difference -400, and 50% chance of -430 when you give a trick away, while a passive lead such as a heart or club results in -400.

 

Assume 8 results, the first 4 of the leaders choosing a spade, and the last 4 of the leaders choosing a passive. Scores will be +50, -400, -430, -430, -400, -400, -400, -400, and the english matchpoints correspondingly 14,8,1,1,8,8,8,8. A spade lead on average gets you (14+8+1+1)/4 or 6 matchpoints, a passive lead (8+8+8+8)/4 or 8 matchpoints.

The passive lead wins.

 

So more people will make a passive lead rather than an aggressive lead. Suppose 12 results, and 4 leaders choose spades, and 8 passive. Add 4 more -400s on the end of that list. Matchpoints are now 22,12,1,1,12,12,12,12,12,12,12,12. A spade lead on average gets you (22+12+1+1)/4 or 9 matchpoints, a passive lead 12 matchpoints. Passive wins out just the same.

 

Even assuming you are in an aggressive field, where 4 lead a spade and only 2 passive, the matchpoints are 10,6,1,1,6,6, and a spade lead gets you (10+6+1+1)/4 or 4.5, while a passive lead gets 6 matchpoints. Passive wins again.

 

You will note that in all cases the ratio is the same, the aggressive lead getting 3/4 the matchpoints of the passive.

 

The above assumes everyone is playing the same contract, as is often the case when it is 3NT. Other considerations come into play when you expect that you will be defending an unusual contract.

 

It all depends on your goals and objectives. Do you want the excitement of some tops and more bottoms, or do you want a boring good result?