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Please help: Valuation of spot cards?

#1 User is offline   perko90 

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Posted 2018-October-03, 21:09

I know I've seen it before - usually in the context of trying to correct Milton point count. Somebody's done some computer analysis to determine the theoretical values of (usually) the honor cards. Something like A=4.4 K=3.0 Q=1.7 J=0.9. What I'm interested in is the relative values of the spot cards for trick taking. Something like T=0.4 9=<.1 8= tiny fraction 7=microscopic etc. Assuming a NT context is fine. My intuition is that 9 is about the lowest spot card that is meaningful toward "texture." But 8's aren't really worth considering. But I'd like to see some computer analysis. Can anyone point me to some?
Thanks in advance.
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#2 User is offline   The_Badger 

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Posted 2018-October-04, 04:00

The K&R evaluator does evaluate 10s, 9s and 8s as far as I know

http://www.jeff-gold...cgi-bin/knr.cgi

Use a standard 1NT hand such as Jx QJx Axx AKxxx and change some of the 'x's into 10,9,8 (especially in the long suit) and different values do appear. As for detailed analysis, I personally haven't any available. Sorry.
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#3 User is online   Cyberyeti 

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Posted 2018-October-04, 04:23

The problem with spot cards is that their value in combination is different to their value in isolation proportionally more than is the case for honours. K1098x, Axx, Qxx, Ax is way better than Kxxxx, A9x, Q8x, A10, K&R evaluates the 2 as 13.6/12.95 but I don't know how it does it.
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#4 User is offline   Tramticket 

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Posted 2018-October-04, 05:59

Why do you ask the question? I'm not sure that any answer would be helpful.

At the end of the day, the only valuation that matters is the number of tricks bid and made. Any hand valuation is simply an aide to help you estimate the number of tricks that you are likely to take. As Cyberyeti points out, the real value of a hand is more than just the sum of the honour cards and intermediate spot cards and many other factors will affect the valuation of the hand as a whole and the valuation of spot cards, including:
- Are the spot cards supporting honour cards or other intermediate spot cards?
- Are the spot cards likely to bolster partner's hand (based on the bidding to date)?
- Are the spot cards in long or short suits?
- Are the spot cards in a suit where our partnership has length or in the opponent's suit (based on the bidding to date)?
- Will the final contract be no trumps of a suit contract?
- Are the spot cards in a likely trump suit or side suit?

You can try to arrive at some fractional mathematics to value your spot cards, but it needs to be simple enough to be usable at the table and flexible enough to change as the auction progresses as well as giving you some added accuracy.

I tend to look at my hand as a whole using a simple Milton Work point count as a starter and assigning positive and negative ticks for various features including the presence and placement of spot cards. I keep it flexible enough to adjust as the auction progresses.
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#5 User is offline   The_Badger 

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Posted 2018-October-04, 07:38

View PostTramticket, on 2018-October-04, 05:59, said:

Why do you ask the question? I'm not sure that any answer would be helpful.


I agree with what Tramticket says generally, but certainly in a no-trump contract spot cards do make a slight difference. I have now remembered that I read somewhere a long time ago that because of the way tricks are established, by covering honours, finesses and the like, the 'lower intermediates' 8s and 9s play a slightly more significant role in gaining a trick in a no-trump contract. That sounds quite obvious and logical, but someone had actually done some analysis to prove this. Where that analysis actually exists I haven't the foggiest.
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#6 User is offline   Tramticket 

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Posted 2018-October-04, 09:28

View PostThe_Badger, on 2018-October-04, 07:38, said:

I agree with what Tramticket says generally, but certainly in a no-trump contract spot cards do make a slight difference. I have now remembered that I read somewhere a long time ago that because of the way tricks are established, by covering honours, finesses and the like, the 'lower intermediates' 8s and 9s play a slightly more significant role in gaining a trick in a no-trump contract. That sounds quite obvious and logical, but someone had actually done some analysis to prove this. Where that analysis actually exists I haven't the foggiest.


Of course spot cards are important, but are you able to apply a meaningful value? I'm not.
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#7 User is online   Cyberyeti 

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Posted 2018-October-04, 10:59

View PostTramticket, on 2018-October-04, 09:28, said:

Of course spot cards are important, but are you able to apply a meaningful value? I'm not.


A 10 with a J and a higher honour I add at least half a point H109x with more honours or cards I add a little, but it's quite subjctive, even H98x I add a little (it can help a lot in the trump suit when you get a 4-1 with stiff J or 10)

Normally I just deduct for poor spots, and largely ignore spots lower than 10 in suits of less than 4 cards unless partner has bid them.
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#8 User is offline   lamford 

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Posted 2018-October-04, 11:40

View PostCyberyeti, on 2018-October-04, 10:59, said:

A 10 with a J and a higher honour I add at least half a point H109x with more honours or cards I add a little, but it's quite subjctive, even H98x I add a little (it can help a lot in the trump suit when you get a 4-1 with stiff J or 10)

Normally I just deduct for poor spots, and largely ignore spots lower than 10 in suits of less than 4 cards unless partner has bid them.

Brian Callaghan advocates what are called Binkie points, with ace 4.5, king 3, queen 1.5, jack 0.666, ten 0.333. Still 40 points in the pack. Unfortunately, if you open a strong 2C with AKTxxxxxxx ATx none none and your partner explains it as strong, you lose 3 IMPs in the UK, even though you have 12.66 Binkie points and 5 controls, you don't have 12 Milton Work points and five controls, which the Blue Bible says you must have.
I prefer to give the lawmakers credit for stating things for a reason - barmar
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#9 User is offline   Tramticket 

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Posted 2018-October-04, 11:47

View Postlamford, on 2018-October-04, 11:40, said:

Brian Callaghan advocates what are called Binkie points, with ace 4.5, king 3, queen 1.5, jack 0.666, ten 0.333. Still 40 points in the pack. Unfortunately, if you open a strong 2C with AKTxxxxxxx ATx none none and your partner explains it as strong, you lose 3 IMPs in the UK, even though you have 12.66 Binkie points and 5 controls, you don't have 12 Milton Work points and five controls, which the Blue Bible says you must have.


Only if you have an agreement to open this 2C. I don't know about you, but I haven't got round to the partnership discussion on what to do with 10-card suits! :)
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#10 User is online   Cyberyeti 

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Posted 2018-October-04, 13:51

View PostTramticket, on 2018-October-04, 11:47, said:

Only if you have an agreement to open this 2C. I don't know about you, but I haven't got round to the partnership discussion on what to do with 10-card suits! :)


I've held 3 in my life and handled them all differently, the one I could have opened 2 I actually passed first in hand.
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#11 User is offline   nullve 

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Posted 2018-October-04, 13:54

View PostCyberyeti, on 2018-October-04, 04:23, said:

The problem with spot cards is that their value in combination is different to their value in isolation proportionally more than is the case for honours. K1098x, Axx, Qxx, Ax is way better than Kxxxx, A9x, Q8x, A10, K&R evaluates the 2 as 13.6/12.95 but I don't know how it does it.

K&R algorithm
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#12 User is offline   lamford 

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Posted 2018-October-04, 15:56

View PostTramticket, on 2018-October-04, 11:47, said:

Only if you have an agreement to open this 2C. I don't know about you, but I haven't got round to the partnership discussion on what to do with 10-card suits! :)

I have an agreement with my regular partners that 2C includes all strong hands that are not necessarily Blue Book compliant, but which we regard as game-forcing. It also includes strong balanced hands with 20-22 or 25+ points. So we could open this with 2C and then rebid 3S, cue force for aces or kings in steps.
I prefer to give the lawmakers credit for stating things for a reason - barmar
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#13 User is offline   RD350LC 

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Posted 2018-October-05, 15:28

View PostTramticket, on 2018-October-04, 09:28, said:

Of course spot cards are important, but are you able to apply a meaningful value? I'm not.

In general, there is no simple way to assign hcp to spot cards. I tend to adjust for distribution, adding points for long suits, and I deduct a point for 4333 distribution.
However, as a humourous anecdote regarding the value of spot cards, there are a couple of funny bridge stories in Robert Darvas and Norman Hart's book "Right Through the Pack", where the significant feature of the stories is that a three is higher than a two. One story involves a balanced hand, and the second one involves an unbalanced hand. One is called "A trey wins by weight" and the other is called "A trey that killed dummy". The stories may be dated, but they are still worth reading.
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#14 User is offline   rhm 

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Posted 2018-October-05, 16:27

View Postperko90, on 2018-October-03, 21:09, said:

I know I've seen it before - usually in the context of trying to correct Milton point count. Somebody's done some computer analysis to determine the theoretical values of (usually) the honor cards. Something like A=4.4 K=3.0 Q=1.7 J=0.9. What I'm interested in is the relative values of the spot cards for trick taking. Something like T=0.4 9=<.1 8= tiny fraction 7=microscopic etc. Assuming a NT context is fine. My intuition is that 9 is about the lowest spot card that is meaningful toward "texture." But 8's aren't really worth considering. But I'd like to see some computer analysis. Can anyone point me to some?
Thanks in advance.


http://bridge.thomas...s/original.html provides double dummy numbers.

The numbers are different for trump contract and notrumps. (they also depend on the level of the contract).

You get relative values from ace down to 8 in the sequence is A,K,Q,J,10,9,8 in the following whole number relations:

Trump contract: 82,51,27,14,6,3,1 (the analysis does not differentiate between trump suits and side suits. However this clearly matters)
Notrump contract: 115,74,43,23,10,4,2

If you normalize this to 40 HCP per deal you have now 7 instead of 4 cards in a suit, on which you divide 10 HCP and you get of course fractions (rounded to one decimal):

Trump contract: 4.4, 2.8, 1.4, 0.8, 0.3, 0.2, 0.1
Notrump contract: 4.2, 2.7, 1.6, 0.8, 0.4, 0.2, 0.1

At notrumps you can say a jack is on average worth half a queen , a ten half a jack, a nine half a ten and an eight half a nine.
These are the figures for double dummy analysis (for declaring not defense) and they of course do not take into account specific suit holdings.
Lower cards gain a lot if they are accompanied by higher cards in the same suit.

You hear often kings are worth more than 3 HCP, but that is not true. The only card which is clearly underrated in standard HCP is the ace.
The king is correctly rated and queens and jacks are overrated, particularly queens at trump contracts.

Rainer Herrmann
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#15 User is offline   nullve 

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Posted 2018-October-05, 17:49

View Postrhm, on 2018-October-05, 16:27, said:

http://bridge.thomas...s/original.html provides double dummy numbers.

The numbers are different for trump contract and notrumps. (they also depend on the level of the contract).

You get relative values from ace down to 8 in the sequence is A,K,Q,J,10,9,8 in the following whole number relations:

Trump contract: 82,51,27,14,6,3,1 (the analysis does not differentiate between trump suits and side suits. However this clearly matters)
Notrump contract: 115,74,43,23,10,4,2

If you normalize this to 40 HCP per deal you have now 7 instead of 4 cards in a suit, on which you divide 10 HCP and you get of course fractions (rounded to one decimal):

Trump contract: 4.4, 2.8, 1.4, 0.8, 0.3, 0.2, 0.1
Notrump contract: 4.2, 2.7, 1.6, 0.8, 0.4, 0.2, 0.1

At notrumps you can say a jack is on average worth half a queen , a ten half a jack, a nine half a ten and an eight half a nine.
These are the figures for double dummy analysis (for declaring not defense) and they of course do not take into account specific suit holdings.
Lower cards gain a lot if they are accompanied by higher cards in the same suit.

You hear often kings are worth more than 3 HCP, but that is not true. The only card which is clearly underrated in standard HCP is the ace.
The king is correctly rated and queens and jacks are overrated, particularly queens at trump contracts.

Rainer Herrmann

I was going to post the same link, but for better comparison with Milton Work it's better to normalise so that 40 hcp is the value of all aces, kings, queens and jacks only. The scales then beome, to one decimal place:

Trump contract: 4.7, 2.9, 1.6, 0.8, 0.3, 0.2, 0.1
Notrump contract: 4.5, 2.9, 1.7, 0.9, 0.4, 0.2, 0.1.
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#16 User is online   Cyberyeti 

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Posted 2018-October-05, 17:56

I would suggest this changes markedly during the auction, the Q of a suit partner has bid (or is in a long suit you are going to use as trumps) is much more valuable than a side unbid Q unless you have the AK and 10 or more trumps. Part of the skill of the game is making the adjustments.
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#17 User is offline   perko90 

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Posted 2018-October-06, 18:39

Thanks guys! That's the stuff I was looking for.
I'm actually surprised the 8 is even worth 0.1 HCP.
Speaking of spot cards, just today, we defended a fun hand where after a few upper cuts, my partner was able to draw declerer's last trump (a 6) with his 7! Down 2 for a good board.
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#18 User is online   Cyberyeti 

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Posted 2018-October-07, 09:26

View Postperko90, on 2018-October-06, 18:39, said:

Thanks guys! That's the stuff I was looking for.
I'm actually surprised the 8 is even worth 0.1 HCP.
Speaking of spot cards, just today, we defended a fun hand where after a few upper cuts, my partner was able to draw declerer's last trump (a 6) with his 7! Down 2 for a good board.


Board I will always treasure was a part score with lots of ruffs and overruffs where I won the last 2 tricks with the 54 of trumps with an opp following with the 32.
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