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Leading from sequences against NT?

#1 User is offline   Dinarius 

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Posted 2018-July-22, 05:24

Against blind NT auctions, are there any views on leading from sequences against NT?

For example, holding K,Q,x,x,x or K,Q,10,x,x is there any received wisdom on, say, leading fourth in the first but K in the second, because you hold 10?

Do spot cards affect whether to lead top or 4th?

If you lead K, and the inevitable J,x,x, appears in dummy, how to you respond as partner? Attitude? Count? (I’m assuming you’re not in an obvious overtaking situation such as A,J,x,)

Any other views on sequence leads against NT?

Thanks.

D.
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#2 User is offline   PhilG007 

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Posted 2018-July-23, 08:29

View PostDinarius, on 2018-July-22, 05:24, said:

Against blind NT auctions, are there any views on leading from sequences against NT?

For example, holding K,Q,x,x,x or K,Q,10,x,x is there any received wisdom on, say, leading fourth in the first but K in the second, because you hold 10?

Do spot cards affect whether to lead top or 4th?

If you lead K, and the inevitable J,x,x, appears in dummy, how to you respond as partner? Attitude? Count? (I'm assuming you're not in an obvious overtaking situation such as A,J,x,)

Any other views on sequence leads against NT?

Thanks.

D.
There are books on this subject One of the best I cut my teeth on long ago is "Your lead Partner" by Ben Cohen and the late Rhoda Lederer

"It is not enough to be a good player, you must also play well"
- Dr Tarrasch(1862-1934)German Chess Grandmaster

Bridge is a game where you have two opponents...and often three(!)


"Any palooka can take tricks with Aces and Kings; the true expert shows his prowess
by how he handles the two's and three's" - Mollo's Hideous Hog
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#3 User is offline   Tramticket 

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Posted 2018-July-23, 09:05

View PostPhilG007, on 2018-July-23, 08:29, said:

There are books on this subject One of the best I cut my teeth on long ago is "Your lead Partner" by Ben Cohen and the late Rhoda Lederer


Archaeologists have pieced together this revered text from fragments found in a series of twelve caves around the site known as Wadi Qumran in the West Bank of the Jordan River. The texts are written on parchment, some on papyrus, and one on copper and were translated from ancient Hebrew and Aramaic languages into modern languages. Analysis of letter forms, or palaeography, was applied to the texts by a variety of scholars in the field. Major linguistic analysis dates fragments from 225 BCE to 50 CE. These dates were determined by examining the size, variability, and style of the text. The same fragments were later analyzed using radiocarbon dating and were dated to an estimated range of 385 BCE to 82 CE with a 68% accuracy rate.

Or did you mean the Dead Sea scrolls?
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#4 User is offline   Tramticket 

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Posted 2018-July-23, 09:33

View PostDinarius, on 2018-July-22, 05:24, said:

Against blind NT auctions, are there any views on leading from sequences against NT?

For example, holding K,Q,x,x,x or K,Q,10,x,x is there any received wisdom on, say, leading fourth in the first but K in the second, because you hold 10?

Do spot cards affect whether to lead top or 4th?

If you lead K, and the inevitable J,x,x, appears in dummy, how to you respond as partner? Attitude? Count? (I’m assuming you’re not in an obvious overtaking situation such as A,J,x,)

Any other views on sequence leads against NT?

Thanks.

D.


More seriously:
- First decide whether you want to lead the suit. You only consider which card to lead once you have decided whether or not to lead a suit.
- The traditional lead from KQTXX is the K. There is a lead-style where players lead their second highest honour, in which case you would lead the Q. This advice woul be relevant for both NT and suit contracts.
- Traditionally the advice would be to lead an honour (the king unless agreement is to lead the second highest honour) from KQXXX against a suit contract but to lead low (usually 4th highest, but some agree to play "3rd and 5th" or other agreements) against No Trumps. Some modern theory (partly based on computer simulations) suggests that leading an honour from KQXXX against a no-trump contract may sometimes be better. Often this will depend on whether you have entries in other suits and the auction as well as the spot card holdings. It is difficult to give definitive advice, without a specific auction and hand.
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#5 User is offline   PhilG007 

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Posted 2018-July-23, 13:39

View PostTramticket, on 2018-July-23, 09:33, said:

More seriously:
- First decide whether you want to lead the suit. You only consider which card to lead once you have decided whether or not to lead a suit.
- The traditional lead from KQTXX is the K. There is a lead-style where players lead their second highest honour, in which case you would lead the Q. This advice woul be relevant for both NT and suit contracts.
- Traditionally the advice would be to lead an honour (the king unless agreement is to lead the second highest honour) from KQXXX against a suit contract but to lead low (usually 4th highest, but some agree to play "3rd and 5th" or other agreements) against No Trumps. Some modern theory (partly based on computer simulations) suggests that leading an honour from KQXXX against a no-trump contract may sometimes be better. Often this will depend on whether you have entries in other suits and the auction as well as the spot card holdings. It is difficult to give definitive advice, without a specific auction and hand.
Or,alternately you could just go eeny meeny miny moe and lead 'moe' and pray (!)

"It is not enough to be a good player, you must also play well"
- Dr Tarrasch(1862-1934)German Chess Grandmaster

Bridge is a game where you have two opponents...and often three(!)


"Any palooka can take tricks with Aces and Kings; the true expert shows his prowess
by how he handles the two's and three's" - Mollo's Hideous Hog
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#6 User is offline   miamijd 

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Posted 2018-July-23, 14:36

Part of it is standard stuff. Part is partnership agreement. Another part of it is IMPs vs MPs.

Standard stuff:

1. Generally, the standard lead from KQxx(x) .. or QJxx(x) .... is low. If you don't find partner with a touching honor, your lead is going to fail one way or the other, and if you do, leading low is better as it will both tell you the position and unblock the suit.

2. The standard lead from KQTxx is the King. From KQT9(x) or KQTxxx, you lead the Q to ask partner to unblock the Jack. But from KQTxx, you can't afford an unblock from Jx in some situations.

3. The standard lead from QJ9x(x) is low, but if you have two outside entries you can lead the Q. The reason to lead low at NT is that it's likely partner will at least have the T, in which case low is better. If he doesn't have A, K, or T, then low still can gain when dummy has honor ten and partner the 9.

At a suit, you would lead Q hoping dummy had the K and partner the A. That situation is not likely vs. NT.

Partnership agreement:

Leads of the A and K depend on partnership agreement. In the US, the traditional method was that A asked for unblock or count (something like AKJTx or AKQTx), whereas K asked for attitude (AKJxx or KQTxx). But I think the more popular modern method is to reverse these, with A asking for attitude and K for count (NOT unblock; Q asks for unblock of J).

MPs vs. IMPs

At IMPs, you are just interested in beating the contract, so low is generally right even from KQ98x.

At MPs, though, you have overtrick considerations, so you might consider leading the K from KQ even without the T if you have good spot cards. Also, at MPs, short suit leads (a la GIB) should be given more consideration than most players give them; they actually give up fewer tricks than long suit leads.

Cheers,
mike
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#7 User is offline   Jinksy 

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Posted 2018-July-23, 16:55

View Postmiamijd, on 2018-July-23, 14:36, said:

Part of it is standard stuff. Part is partnership agreement. Another part of it is IMPs vs MPs.

Standard stuff:

1. Generally, the standard lead from KQxx(x) .. or QJxx(x) .... is low. If you don't find partner with a touching honor, your lead is going to fail one way or the other, and if you do, leading low is better as it will both tell you the position and unblock the suit.

3. The standard lead from QJ9x(x) is low, but if you have two outside entries you can lead the Q. The reason to lead low at NT is that it's likely partner will at least have the T, in which case low is better. If he doesn't have A, K, or T, then low still can gain when dummy has honor ten and partner the 9.


Bird and Anthias found a substantial DD advantage for leading an honour from KQxx(x), and a slightly reduced (but still present) advantage from doing the same with QJ holdings.

FWIW I've never heard anyone advocate anything but an honour from QJ9 holdings.
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#8 User is offline   miamijd 

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Posted 2018-July-23, 17:16

View PostJinksy, on 2018-July-23, 16:55, said:

Bird and Anthias found a substantial DD advantage for leading an honour from KQxx(x), and a slightly reduced (but still present) advantage from doing the same with QJ holdings.

FWIW I've never heard anyone advocate anything but an honour from QJ9 holdings.


With respect to KQxx(x), I would be interested to know whether the advantage they found was in tricks taken or contracts defeated. I would bet it would be tricks taken, which is vital in MPs, but not as much in IMPs.

At lot of it depends on the auction and whether you are playing IMPs or MPs. At MPs, if you think the opponents are strong, K from KQxx(x) is often right to cut down on the overtricks. At IMPs, where you just want to beat them and don't care about overtricks, if you have determined that your best chance is to set up the KQxx(x) suit (often it isn't), then you are better off leading low.

With respect to QJ9xx, it also depends on the cin practice, low is only likely to lose in these situations:

1. Declarer has AKT or AKx with the T in dummy
2. Declarer has HT(x) (H=A/K) and dummy has Hx(x) (one of them has to have three)
3. Dummy has HT tight and declarer has Hxx


Low will do better in the following situations:

1. Partner has Ax, Kx, or Tx
2. Partner has A, K, or T singleton
3. Partner has AK, AT, or KT doubleton
4. Partner has 9x or 9xx with HTx in dummy (declarer will play your partner for Q9 or J9, not QJ)
5. Dummy has AKT (declarer is not likely to hook the ten)

If you are looking to maximize your tricks, Q may be better. But if you are looking to set up your suit to defeat a contract, low is going to work more often.

Cheers,
Mike
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#9 User is offline   Tramticket 

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Posted 2018-July-24, 00:56

View Postmiamijd, on 2018-July-23, 17:16, said:

With respect to KQxx(x), I would be interested to know whether the advantage they found was in tricks taken or contracts defeated. I would bet it would be tricks taken, which is vital in MPs, but not as much in IMPs.

At lot of it depends on the auction and whether you are playing IMPs or MPs. At MPs, if you think the opponents are strong, K from KQxx(x) is often right to cut down on the overtricks. At IMPs, where you just want to beat them and don't care about overtricks, if you have determined that your best chance is to set up the KQxx(x) suit (often it isn't), then you are better off leading low.


They analysed:
KQ652
874
92
AT2

against (1NT), Pass, (3NT).

They find that there is an advantage in leading the king at IMPs as well as matchpoints (33.7% chance of defeating the contract as against 30.5% for a low spade). They do acknowledge a weakness of double dummy simulations on this type of deal - it might save declarer a guess on a hand where the spade suit is for example:



Their analysis suggested that some, but not all, of the advantage will be lost. I also think that a low card is easier for partner to read.

Overall, I think that it is probably surprisingly close. My instincts to lead low have been challenged by this type of analysis.
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#10 User is offline   msjennifer 

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Posted 2018-July-24, 02:13

Firstly if the Jxx are in dummy then Partner cannot have AJX.We found that playing the second highest card when Partner leads an honor and you have nothing to unblock has helped us a lot.
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#11 User is offline   miamijd 

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Posted 2018-July-24, 10:59

View PostTramticket, on 2018-July-24, 00:56, said:

They analysed:
KQ652
874
92
AT2

against (1NT), Pass, (3NT).

They find that there is an advantage in leading the king at IMPs as well as matchpoints (33.7% chance of defeating the contract as against 30.5% for a low spade). They do acknowledge a weakness of double dummy simulations on this type of deal - it might save declarer a guess on a hand where the spade suit is for example:



Their analysis suggested that some, but not all, of the advantage will be lost. I also think that a low card is easier for partner to read.

Overall, I think that it is probably surprisingly close. My instincts to lead low have been challenged by this type of analysis.


Ac is a big card in their analysis. If you have an outside entry, I agree it's close with five. If you have two outside entries, definitely the K is better. With no certain outside entry, you have to lead low.

Cheers,
Mike
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