Join Bridge Winners
All comments by Eugene Hung
You are ignoring the author of this comment. Click to temporarily show the comment.
Thomas - I meant 3+ clubs, sorry, as Kit specified.

Geoff - I personally agree with you. I think re-running the simulation with 9 HCP or the other two 2 aces plus club support would be more interesting and realistic. I could also customize it based on club length if you think that's a good idea (i.e. if 4 clubs, 9+ HCP, if 5 clubs, 8+ HCP ok). Or if you can specify honor orientation parameters (all HCP aces or in clubs) let me know, my simulation can be quite specific.

Peter - I can also do a NV simulation at the same time by assigning a hypothetical score. Ill do that in my next run.

Rainer - 1000 deals is not nearly enough sample size to generate consistent results. I actually ran 1000 + 1000 first (which only took a minute) and noticed the results varied widely. I then ran 20000 + 20000 and the two results sets were fairly consistent, so I felt more comfortable reporting based on the last 40000 hands I generated, but even 20000 would not have changed the results appreciably. 20000 hands took a long time to generate (roughly 20 minutes), but I felt much more confident about the results. Can you rerun your simulation with 20000?
March 11
You are ignoring the author of this comment. Click to temporarily show the comment.
I had a little time this evening so built and ran the DD simulation using my homegrown simulation software and was surprised at the results. I have already built functions to simulate my style in opening, passing, and passing in overcall situations. I gave North 10-11 HCP, 4-5 hearts, 3 clubs, no shortness, and a hand a standard expert playing 2/1 would not open. (The actual North hand was too strong for this simulation.)

On 40,000 deals:

Makes 3NT = 16253 (40.6%)
Down 1 = 13179 (32.9%)
Down 2 = 6668 (16.7%)
Down 3 = 2347 (5.9%)
Down 4+ = 1553 (3.9%)

Makes 3C = 36470 (91.2%)
Down 1 = 3240 (8.1%)
Down 2 = 285 (0.7%)
Down 3 = 5 (negligible)
Down 4 = 0

Vulnerable, the average IMPs from bidding was +0.448 IMPs / board, with a standard deviation of 8.1 IMPs. This factors in going down multiple tricks in 3NT (which occurs over 25% of the time DD, but 3C itself is not cold). So under this simulation, bidding vulnerable at IMPs is slightly +EV.

Unsurprisingly, bidding wins IMPs 40.6% of the time and loses IMPs 57.6% (push the rest), so passing is correct at matchpoints.

Looking at the hands, the following concepts stand out:

1) The HCP are usually spread fairly evenly around the table. With North holding 10-11, South exactly 11, and East a passed hand (at most 11, and no shapely 11s or 10s), West is guaranteed to hold at least 7 HCP and usually has 8-11.

2) My simulation throws out hands where I judge West would have overcalled or doubled 1C at the 1-level, not vulnerable. (I wrote this function a long time ago to generate guaranteed passes for competitive bidding on BBO and didn't write one for vulnerable conditions.) This was probably too aggressive given that the original conditions had West vulnerable, but it's still a significant factor that was not mentioned in this thread, because coupled with (1), the odds of West having a good 5-card suit to lead are not high, because he probably would have overcalled. The sim still generated hands with 5-card suits for West, but they were usually mediocre to bad suits or containing bad holdings like doubleton QJ of clubs.

3) I feel the DD nature of the simulation overrates the chances of the defense given that the opening leader is less likely to be leading the suit that needs to be established, but that isn't backed by analyzing the data, just feeling. Then again, the sim probably overrates the chances of declarer picking up the club suit for 6 when missing the queen. If I run this simulation again, I can check to see how often North holds the club queen given that he holds 3+ clubs with 10-11 HCP.
March 11
Eugene Hung edited this comment March 11
You are ignoring the author of this comment. Click to temporarily show the comment.
The original comment in this thread has been flagged by the community many times for perceived inaccuracy. That is not a valid reason to remove content. If you feel someone is posting incorrect information, you can merely post a (polite) response explaining why you feel they are incorrect and let the discerning reader decide. Please only flag content that violates our guidelines. That is content that is rude, offensive, off-topic (has no relation to bridge), spam, or violating copyright. Talking about politics and religion usually, but not always, violates one or more of these guidelines.
March 11
Eugene Hung edited this comment March 11
You are ignoring the author of this comment. Click to temporarily show the comment.
Moved to Site Feedback at request of the community.
March 10
You are ignoring the author of this comment. Click to temporarily show the comment.
Sorry, we agree this is a problem, but we currently don't have the resources to dedicate to fixing a low-priority item such as this one.
March 10
You are ignoring the author of this comment. Click to temporarily show the comment.
Comment by Mike Ma flagged by the community as an irrelevant political reference and removed.
March 10
You are ignoring the author of this comment. Click to temporarily show the comment.
Comment by Ellen Kent flagged by the community for violating copyright, and removed. Please do not copy information verbatim from other sources for public consumption, especially information from behind a pay wall. A link is sufficient.
March 9
You are ignoring the author of this comment. Click to temporarily show the comment.
Comment by John McWhinnie flagged for bringing the discussion into a non-bridge political discussion area, and removed. This site is not the place to bring up political discussions that offend a significant number of our users without providing useful information to bridge players. The topic of coronavirus itself is acceptable because it is impacting bridge tournaments, but extending that discussion out of the bridge realm into observations about specific politicians is not acceptable.
March 9
You are ignoring the author of this comment. Click to temporarily show the comment.
Comment by Richard Willey flagged by the community for containing a personal attack, and removed. While there's a lot of understandable emotion in this topic, ad hominem attacks will not be tolerated here.
March 9
You are ignoring the author of this comment. Click to temporarily show the comment.
Comment by Jim Perkins flagged by the community for containing non-bridge-related political content, and removed. In general, if a comment references a contemporary politician and there is no direct link to bridge, then it will be removed as soon as someone flags it.
March 7
You are ignoring the author of this comment. Click to temporarily show the comment.
Ray -

In general, we only create a forum if :

1) The forum needs to go to a private subset of people and not the entire Bridge Winners population. For example, the recently created Junior Training Forum, or the USBF discussion forums, which restrict ability to read or post to its members.

2) The forum is public (open to all), but contains a significant number of posts that would be better off lumped together, and will continue to do so for a long time. Examples of this would be the Intermediate Forum or the Partnership Desk forum. Both of these forums provide a service for people looking for a specific type of article. While it also has the effect of removing these types of articles from the front page, the primary purpose of these forums is constructive, to gather articles of a specific type in a location for someone to seek them out.

Remember that forums are permanent and cannot be undone. It would look silly right now to have a SARS forum, an Ebola forum, a Zika forum, or even a 2016 Cheating Scandal forum. A forum needs to have sustainable long-term interest to justify its creation. Let's see how this plays out before committing to a forum. For now, if you can't stand seeing coronavirus threads, you don't have to click on them, just like Laws discussions or Director call discussions or Assign the Blame polls.
March 6
You are ignoring the author of this comment. Click to temporarily show the comment.
This was flagged as a bidding poll and will be removed. Please repost as a bidding poll.
Feb. 27
You are ignoring the author of this comment. Click to temporarily show the comment.
Comments by Lars Andersson and Ron Steele flagged by the community for containing references to a contemporary political figure without relevance to bridge. All such posts WILL be removed immediately.
Feb. 27
You are ignoring the author of this comment. Click to temporarily show the comment.
I agree slow play is a bane but some time for thought is also part of the game. Many hands can be handled with normal time controls but some positions are really complex and deserve some thought, especially if you might have to factor in what the other table(s) might be doing. What I'd like to see is something I've seen used in poker tournaments: some sort of time bank that could be used once per session for the really complex positions in critical contracts, giving extra time on a hand that really needs it.
Feb. 16
You are ignoring the author of this comment. Click to temporarily show the comment.
I don't know what the power lead is in Junior Standard, but I'd lead the top spade that isn't the power lead. Seeing the dummy is so important against notrump.
Feb. 16
You are ignoring the author of this comment. Click to temporarily show the comment.
While I agree that our auction does not in itself create a force, one could argue that the opponents' does. East is a passed hand, and West has made a (presumably) weak jump overcall, and they have bid to the 5-level at equal vulnerability. I feel it's reasonable for a partnership to define that when opponents go to the 5-level with a preemptive call opposite a passed hand, and they are not unfavorable, they are saving, not bidding to make, so this could be treated as a forcing auction. This is a good area for partnership discussion.
Feb. 15
You are ignoring the author of this comment. Click to temporarily show the comment.
Yes. Even though 3 might sound non-forcing (as a rebid of 2 would be in standard bidding), it is impractical to cater to stopping on a dime in the undesirable contract of 3 after partner shows near-game values and six good hearts. Most responding hands have enough to force to game or can tolerate passing partner's jump rebid. There are a few hands with minimum values, extra spade length, and shortness in partner's suit that would prefer that 3 be non-forcing. However, these are outnumbered by the hands that have enough to force to game but want to explore spades as an alternative strain, such as this one.
Feb. 14
You are ignoring the author of this comment. Click to temporarily show the comment.
Moved.
Feb. 14
You are ignoring the author of this comment. Click to temporarily show the comment.
I don't know what bid is definitely right, but 5 is wrong. How much better could our hand be given that we've limited it to a non-mixed raise in competition? There is no way you can consistently reach the right spot if you bid the same way with this hand and with the worst hand in your range (something similar to Kxx Jxx Qxxx xxx).

Remember, partner could have cue-bid 4 or 4 but did not - they forced us to the 5-level missing the AJT of trump and another ace (likely not pulling full value, but an ace is still an ace). Both minors must be controlled, or partner would have bid the minor they control first (then follow up with 4 to highlight the problem). There are very few hands opposite a proper 4 call where you have no play for 6. Even Kevin's hand with the minors switched so that you don't have the perfect T98x mesh opposite AJx still has play (most 3-3 clubs, doubleton QJ in either hand, or doubleton quack with overcaller - around 43%). So I'm fine with forcing the auction to 6 and showing my hand with 5 so that partner, who knows what 4 is based on, can make an intelligent decision.
Feb. 13
Eugene Hung edited this comment Feb. 14
You are ignoring the author of this comment. Click to temporarily show the comment.
Comments removed for being political without any connection to bridge, and likely to spark even more posts in that vein.
Feb. 13
.

Bottom Home Top