Tracking system successes/failures systemic approach
#1
Posted 2012-June-28, 11:04
I just started a project where I was tracking the success/failure of all of our partnership's 3 and 4 level preempts. I noted the actual imp result, the par imp result, the difference between the two, whether the preempt was standard or not standard, and in what way, who the opponents were, the date, and whether there was a reasonable opportunity for further gain which we did not exploit from our preempt (ie, we didn't double/sac when it was clearly indicated). Edit: I also included the vulnerability
Against good opponents, it seems our 3/4 level preempts gained an average of a little more than 2 imps vs par, and that the biggest gains were non-standard preempts (preempts with an outside control, or with an unexpected number of cards in the suits) - normal preempts made up 3 of the 10 results in the time tracked, and had a net gain/loss of 0 against par. The biggest loss came from a preempt where we had an ace and a void outside of our suit - that was too much offensive potential, we did not get to game on a hand where slam makes. Hands with 1 flaw turned out to be huge winners, but again, the sample size was relatively small.
#2
Posted 2012-June-28, 11:35
CSGibson, on 2012-June-28, 11:04, said:
I just started a project where I was tracking the success/failure of all of our partnership's 3 and 4 level preempts. I noted the actual imp result, the par imp result, the difference between the two, whether the preempt was standard or not standard, and in what way, who the opponents were, the date, and whether there was a reasonable opportunity for further gain which we did not exploit from our preempt (ie, we didn't double/sac when it was clearly indicated).
You also need to include whether you missed out on an opportunity to gain because of your style, or you gained because of your style.
For example, I play a very random and aggressive style of pre-empt in certain positions and vulnerabilities. This means I pre-empt more often, but it also means that partner does not always save (or raise) when it is right. So I might gain on hands where a disciplined pre-emptor has to pass (and that is worth tracking) but I lose on hands where a disciplined pre-emptor can save accurately.
Also, of course, it's really hard to say if you should have saved or not. It's not uncommon for a technically wrong sacrifice (800 against game, or against a non-making game) actually wins because they bid on; or at least breaks even because they bid on and make the same 11 tricks they had al along.
And what about hands where you put them under pressure and they got it right? If you pre-empt and oppo guess well to bid a making slam you haven't directly gained from the system, but you've made their life harder which is worth something in later boards that set.
#3
Posted 2012-June-28, 13:55
#4
Posted 2012-June-28, 14:31
JLOGIC, on 2012-June-28, 13:55, said:
By par I don't mean double dummy par, but by likely result - for example, there are two lucky slam hands that I didn't include as par because it was unrealistic to get there or expect to make (though if our preempt pushed them there and they made it, I would obviously include that as a loss). So I try to include play decisions as part of par, which makes calculating par on some hands impractical. There are some hands where there are too many permutations in both play decisions and bidding decisions to calculate one par, on those I tend to give a range of likely results as well as the actual result. This is obviously more time intensive than the simplistic model that I think you were assuming, but also more valuable in evaluating the effectiveness of our preempting decisions.
#5
Posted 2012-June-29, 03:44
It is a fair bit of work, even without tracking the hands and analyzing the auctions that didn't happen. I tracked a few thousand hands at one point in time (just for partner, play, field strength, contract, MP result) but it became cumbersome, especially coming back from a national when I hadn't tracked anything while away from my computer.
#6
Posted 2012-June-29, 09:21
CSGibson, on 2012-June-28, 11:04, said:
You'd also need to track the instances where you chose not to use your systemic device. For instance, if you want to track your preempts, you also need to track those borderline hands where you choose not to preempt. Or, if you don't preempt with a [void, outside controls, etc.] track the results for whatever you did open with these hands.
#7
Posted 2012-June-29, 09:25
TimG, on 2012-June-29, 09:21, said:
I suspect the solution heavily depends on your skill level and the homogeneity of the field you are playing in. While I agree that the comprehensive approach is better, separating out systemic factors from the general noise of factors like opponent competence is probably practically impossible.
So for example, I track abnormal results and also where we make a highly unusual pre-empt (I define 'highly unusal' as 'only people in the room to open the hand'). Conversely, I've never bothered really trying to evaluate the effect of the multi 2D if our opponents got to the normal spot. It's possible that the 2D might have made it easier than a natural weak 2S for example, but determining that for sure is impossible.
#8
Posted 2012-June-29, 12:01
Cthulhu D, on 2012-June-29, 09:25, said:
You will need to track the cost of not being able to open 2D with whatever multi replaces to get a true value of multi, not just the results when multi 2D is opened.
#9
Posted 2012-June-29, 20:30
#10
Posted 2012-June-30, 17:37
OP asked "How", but I don't see any answer here.
#11
Posted 2012-July-09, 00:18
CSGibson, on 2012-June-28, 11:04, said:
My opinion on this topic is that every single bridge player, regardless of skill level, subconsciously tracks systemic successes and failures. Why do I say that? Easy: partnerships are forever making system changes, tweaks, experimenting with new gadgets/systems etc. The stuff that works is retained. The stuff that doesn’t work gets discarded. These systemic changes tend to escalate in number as the partnership steadily gets better. The reasons are straight forward –
1. Your bidding system needs to be optimal to get your side to the best contract.
2. Your defensive agreements also need to be optimal to either defeat the contract or to prevent overtricks.
My guess is that it is only once you reach international level that the systemic changes drop off substantially. By then you and partner knows what works best for you.
#12
Posted 2012-July-09, 02:09
32519, on 2012-July-09, 00:18, said:
Are you sure they make system changes, tweaks, experiment new gadgets because they subconciously track their systemic successes/failures? Or is it because it is easier to make changes to system and think it is the system/style/convention that sucks instead of improving their judgement/logic/card play ?
Imo the majority falls into 2nd category.
"It's only when a mosquito lands on your testicles that you realize there is always a way to solve problems without using violence!"
"Well to be perfectly honest, in my humble opinion, of course without offending anyone who thinks differently from my point of view, but also by looking into this matter in a different perspective and without being condemning of one's view's and by trying to make it objectified, and by considering each and every one's valid opinion, I honestly believe that I completely forgot what I was going to say."
#13
Posted 2012-July-09, 02:40
That's why poker players use statistical tools (or just Excel) instead of relying on their subconscious.
#14
Posted 2012-July-09, 03:47
#15
Posted 2012-July-09, 04:35
wclass___, on 2012-June-30, 17:37, said:
I use Excel. You don't need anything more than a few columns for categorisation, the date, event, hand and result. Any analysis can be done with filters and pivot tables.
Quote
He doesn't seem to be complaining.
#16
Posted 2012-July-09, 04:59
Zelandakh, on 2012-July-09, 03:47, said:
You certainly have a valid point here although not 100% in line with my own personal experiences.
I have been a member of the F2F club in my home town for 20 years now. Over those 20 years, members have come and gone. Apart from myself, there are only 5 other members who are still members of the club who were there when I joined. One of them is my current F2F partner. The remaining 4 are by no means going to set the world on fire, either with their standard of play, or with the system they play.
Here I am forced to agree with you. Over the 20 years that I have known them they have made limited changes to the system they were taught. The key word here is limited. On the rare occasions they ended up in new partnerships, the new partner “forced” them into trying something different. When the “something different” proved to be better than what was previously used, it became the new standard.
Amongst the players who have come and gone, there have been a fair amount good players and some really bad ones (hopeless would probably be a better description). Yet even amongst the hopeless players I would often find them (usually in the bar) discussing some of the hands played trying to figure out between themselves a better way of doing things, usually confined to the bidding. They never manually tracked the changes made, whether on paper or on computer, but changes certainly were made.
Based on my own experiences I still believe that subconsciously we all track system successes and failures.
#17
Posted 2012-July-09, 07:53
32519, on 2012-July-09, 04:59, said:
It's obvious from every field of human enterprise that the evaluations based on 'well, I reckon' without a solid statistical or theoretical underpinning are wrong. Attempting to assess your systematic failures on this basis is ridiculous. Pick any random sport to see this in action, though the statisticians are taking over now.
#18
Posted 2012-July-09, 23:49
Cthulhu D, on 2012-July-09, 07:53, said:
Let me give you another example from personal experience and what I keep witnessing amongst the players in my home town.
1. The better or stronger the players are, any changes made to system agreements are –
.a. First verbally discussed.
.b. Then agreed upon.
.c. Then written down on a piece of paper (initially on the back of a personal travelling score sheet).
.d. Before finally updating the system change on a computer where the full system agreements are kept.
.e. A printout of the full new agreement is made for both partners.
2. Conversely the worse or the weaker the players are, any changes made to system agreements are –
.a. Verbally discussed.
.b. Agreed upon.
.c. No written record is kept of those new agreements resulting in:
....i. Either or both partners forgetting what they had verbally agreed upon.
...ii. Fights and arguments at the table as to who it is that screwed up.
..iii. Inconsistency from week to week regarding those agreements (what applied last week no longer applies this week).
...iv. The fights and arguments upsetting the partnership to the extent that their results for the evening are worse than they normally are (as the score keeper, on numerous occasions I have seen their results drop from the low 40s to the high 20s because they are now angry with each other).
The better a player is, whether it be golf, tennis, athletics etc they inevitably have a top quality coach to identify any weakness or whatever in their game. The really bad bridge players I have known were unable to fathom why they were last week in and week out.