Bridge: Up for a challenge?

The Sandbox Games
1

This is a carry-over of this AO thread http://204.232.242.165/actuarial_discussion_forum/showthread.php?t=343568

Here’s post 1 of that thread, modified for some subsequent changes.

*Instead of just challenges against bots, Klaymen and I have played over 20 challenges against each other. 16 board imp format, we hold the same cards at separate tables. All other players are bots. He’s up a few matches. I’m up a few imps.

*We can do this as multi-way challenges.

If you are interested, let me know in this thread or by PM. Include your BBO id.

Klaymen and I have been averaging a less than 24 hours per match (from when challenge issued to when challenge complete. I think my actual playing time for 16 boards is slightly over an hour.) The mechanics of a 2-player challenge is that the challenge expires 72 hours after the challenge is issued if not completed. Multi player challenges likely work that way too.

If you don’t want a multi player challenge but would like a 2 player challenge, it’s all good.

Challenges could also be MPs or total points. I prefer imps but could be flexible.

Most recently, we have had two 5-way challenges going, among myself, oirg, Abstract Actuary, Numbers Nerd and procrastinator. There have also been 2-way matches between me and AA, NN and procrastinator. In addition to those and Klaymen, Been There Done That, Phileas Fogg and jeremiahsjohnson played some, and BTDT still expects to play some future matches.

Recently most of the matches have taken more than 48 hours before all participants have finished.

Skill level? Who knows? NN is ACBL flight A, I’m ACBL flight B, and each of us has won our district’s Grand National Teams flight at least twice. My impression is that procrastinator and NN have the most wins in the group challenges, but oirg and I have some. AA is not as experienced, nor has he played in this group as much. I’m not sure whether he’s won any, but he’s certainly beaten me in some 2-way challenges and finished second in 5-ways.

You do have to put up with the bots’ idiosyncracies, usually a bad thing when they are your partner, especially on defense. Whatever they do for or against you, they will do exactly the same at the other tables, if bidding and play are the same up until that decision.

2

I report all the match results in that AO thread, but I’m going to start reporting them here, too. Good for post count, and the AO is on its last legs.

One thing I didn’t specify in that first thread: I’ve got a lot of capacity left to host 2-way challenges. A group challenge can be a maximum of 5 players, including the host, and an id can host only one group challenge. I have (:cough: :cough:) two BBO ids, so I can only host 2 group challenges at a time. If you want to play, we’ll make it happen but for example you will never be in a single challenge against all 5 of us. However we split into groups, each challenge will play different hands.

3

Most recent results (of 5-ways): NN wins the regular challenge with +21.25. I win the Declarer Only challenge with +29.75.

Both were margins of at least 10. I reissued both.

That means NN gained an average +21.25 imps per opponent over the 16 boards. “Declare Only” (the challenge I won) is a challenge where we don’t bid. The bidding is given to us, and we just have to try to make the contract.

“Declare only” is available only in group challenges. 2-way challenges are always bidding and play. One other thing I didn’t mention, applicable to all these challenges with bots. If your bot partner becomes declarer, so that your hand is dummy, you chose the cards to play from declarer’s hand as well as dummy’s.

Another thing I didn’t mention: bidding. When playing with people, you and your partner agree in advance, generally, what various bids mean. With some limits, you can agree on whatever you want. With bots, the agreements are specified in advance, and almost never change (maybe updated once a year?). For example, like it or not, a 1NT opening bid shows 15-17 HCP (common but not universal among humans) and a generally balanced hand (nearly universal among humans) which would often include a 5-card major (in my experience in Pennsylvania, not a majority agreement among humans, but also not unheard of). You don’t have to remember all those agreements during the challenges: using your cursor you can always find out what the agreements are.

4

Wow. Low scoring boards with many pushes. Across the three 2-ways, only 1 swing of 8 imps, and that one in the tightest (net imp difference 2) match.

I beat NN 11-9, beat AA 4-0, lost to procrastinator 16-0.

All are reissued.

5

Both Group Challenges were close. In Declarer Only, I won with +22.50, but it was a margin of only 2.50. In the regular challenge, procrastinator won with +13.50, but by only 2.25. I reissued both.

There were two really rare deals where catering to a very unlikely distribution (but still doing well on normal distributions) paid off. On board 4, I was very pleased to realize I could give myself an extra edge by a play that gained only if hearts were 5-1 with a singleton 10 (but never cost). Hearts were that way. Was it a pickup? No, and I didn’t really expect it to be, since clubs were very favorable for our side and we all took 13 tricks. What I didn’t expect (no offense intended, probably should have expected) was that NN and procrastinator would also find that slight extra edge in hearts.

Could lightning strike twice in the same 16 boards? Board 14, a chance to cater to an even less likely heart situation: 5-1 with a stiff A, and the stiff A specifically with my LHO. This time, we couldn’t cater to that with complete safety. Probably we could, but if we played for it and the bots defended flawlessly, it might cost. (Wasn’t likely to matter either way. Mattered only if diamonds also broke 4-0.) Sure enough, hearts were 5-1 with LHO holding the stiff A, and diamonds were 4-0, but I didn’t cater to that. No one else did either.

6

Close 2-way challenges. I beat NN by 1, lost to procrastinator by 4, lost to AA by 4.

:swear: That AA is so lucky! I lost 10 imps when he bid a slam I stayed out of, that he made only because both his finesses were onside.

Then he set a vul game because declarer at his table was an idiot. Declarer’s (LHO’s) trumps are J9543; dummy has K1086. CHO has Q72, and AA has the stiff A.

Trick 2 of the hand: 9 (from declarer; LHO) - 7 - 8 - A,
Trick 6 of the hand: J (from declarer; LHO) - 2 - K - pitch. Maybe AA would have tried the grosvenor coup of winning the A first from AQ doubleton, if he had it, but not this time. Contract down 1.

Grosvenor gambit, from Wikipedia: https://en.wikipedia.org/wiki/Grosvenor_gambit

But I can’t complain too much about those two hands.

Spoiler Text

He needed two finesses only because trumps were 5-0. 3-2 and the slam is cold; 4-1 and he likely needs only 1 of 2, with some slight additional handling risks. So it was an excellent contract.

And the misplay of that trump suit was identical at my table, no swing.

I reissued all three.

BBO has some special activities this weekend.

7

I won both group challenges, the regular with +19 and the declare only with +15. I can’t say what the margin was (conceivably one or both was even tied). BBO shows my rank as 1, but won’t show the results. From previous experience, the rank would show as 1 even there was a tie.

You (the other participants, if they’re here) should be able to see your own and others’ results, board by board if you want. I can see those, but I’m not about to add up everyone’s results for 16 boards to see what everyone else’s total was.

I reissued both challenges.

8

2-ways: I lost to NN by 25, lost to procrastinator by 3, beat AA by 23.

The AA match featured a 17-imp gift to me. At both tables, opps reached 6NT, vul, and got a heart lead, best for the defense whichever side was declarer because it attached an entry. (It was different sides at the two tables). Still 12 tricks should have been easy on any reasonable play, as the cards lie, even though declarer’s chances, just looking at his hands, would not look so good (basically needs a 3-3 break in either black suit; doesn’t even matter if you try the one that doesn’t break first, as long as one does. Would need a miracle if neither is 3-3.) His declarer was not an idiot. Mine was.

I reissued all three.

9

5-ways: AA wins the regular one with +12. procrastinator wins the Declare only with +10.75. Not surprisingly, neither is a margin of 10 over 2nd place.

I reissued both.

10

2-ways: +16 vs NN, +6 vs AA. And :swear: -9 to procrastinator in a very swingy match, 41-32.

So why the :swear:? Board 16 was just a push, opps playing 2D making. But (at least as the cards lie) it should have been a pickup for me. At trick 3, I found the defense that left declarer no chance. Make that almost no chance. No chance other than absolute idiocy by my CHO, so the contract came home. procrastinator didn’t find that defense so his LHO had an easy time. On other lies of the cards, procrastinator’s play might have gained, but in most of those gains it would just mean fewer overtricks in a contract always making.

But that push wasn’t all. -11 where I misdefended, as the cards lie. I couldn’t believe it. Defending 4S, we have the first 3 tricks (club, club, club ruff), and partner shifts to a low diamond through dummy’s QJ10. Surely he wouldn’t have underlead the diamond ace, the setting trick, so I ducked my Kxxx.

Only he had underlead the ace, and ducking was fatal to the defense. Declarer was void, but he got a pitch. I was so pissed at CHO at the time, but realized even before the next deal that CHO’s play would beat the hand, double dummy, that my playing the K could not have cost, even if declarer had a stiff A, and that had CHO led the A instead of a low diamond, that would cost the contract. (Declarer would ruff, then taking a ruffing finesse against my K, to get his pitch.) Almost certainly CHO should just have led a heart instead of a diamond, but a diamond perhaps could have been right.

So when saw that I had lost 11, I was all set to congratulate procrastinator, who had set 4S X. Surely the first 3 tricks would go the same, presumably CHO led a low diamond at trick 4, and procrastinator must have worked out to cover with the K. Good for him. Usually the K would be awful, but on the bidding here it would have been the right play.

But no. Tricks 1-3 were the same. But procrastinator had made an aggressive balancing double of 4S. Maybe that should have worked better for the defense, as on that bidding CHO should be sure he had a set with a heart at trick 4. Did that double, making the defense easier, win the board for him? No, CHO tried to cash the ace of diamonds, which should have cost the contract. Should have, but didn’t, as declarer tried a heart hook into the strong hand, rather than the ruffing finesse in diamonds.

A glutton for more punishment by bots, I reissued all three.

11

The winners in each group challenge won by over 10 imps. I won the regular challenge with 25.75. procrastinator won the declare only by 22.75.

We competitors should look at procrastinator’s play on board 10, where he was the only one to make 4S. I was surprised to see how. Reasonable successful lines occurred to me, so I wondered which he took.

We all could make it at trick 2, where the winning play (ruffing high rather than risk an overruff) was exceedingly unlikely to be necessary (only if hearts were 8-1) but also exceedingly unlikely to cost (costing only if RHO, who surely had at least 6 hearts, also had all 3 of the missing trumps). But no, procrastinator did not find that.

Next chance at trick 3, when LHO continued a low diamond thru dummy’s A10x with us holding K8x. As it turned out, if we play the 10 it holds, and we make the game. Then 10 is the wrong play, so it’s good that none of us including procrastinator found it.

After that I didn’t see how procrastinator would get home, but he did, and with the play that would get admiration from the kibitzers than the more prosaic line the rest of us took. He stripped the hand, exited a diamond, which had to be won by LHO, who then had to lead away from his club K. Making. The rest of us led toward the club Q, setting up a diamond pitch if RHO had held the club K.

Which play is better? His worked, which is what counts. Trying to estimate odds depends on whether RHO would bid as he did (open 1H, then rebid 2H after P-P-Dbl, then sell out to 4S) with x AKQJ10xxx if he also has the club K or if he does not have it. (There might also be some inferences available from LHO playing a diamond instead of a club at trick 3, but on our side’s actual hands a club lead at trick 3 would have been fatal wherever the club K was, so maybe the diamond was normal defense…)

I reissued both group challenges.

12

2-ways. +6 vs AA (based on only 3 boards complete when time expired). +11 vs NN. -7 vs procrastinator.

I reissued all three.

14

Close results in the 5-ways. Declare-only 5-way, procrastinator with +4. Regular 5-way, AA with +8.5, but a win by less than 1. :swear: in the Declare-only, I was 4th, but should have won until I went hopeless in the 4 card end-position on the last hand, going down instead of making. Still won an imp, since no one else had a chance to make with 4 cards left. For a good reason, since most of them took a better, though unsuccessfull, line earlier.

3-ways: lose to NN by 3, to AA by 5. Win by 10 vs procrastinator. I reissued them all.

Very strange against procrastinator: CHO handed declarer (RHO) a vul 3NT contract that almost surely was going down without the gift. It could not make, double-dummy, had CHO not presented that gift, but there would be some chance that I would not find the right defense later. So how did I lose only 5 imps when CHO handed RHO a vul game. So how did I lose only 5 imps, given that the contract was also 3NT at procrastinator’s table?

spoiler text

procrastinator’s side declared 3NT, down 4, vul, undoubled.

15

Both 5-ways were won with +20.25, neither one a margin of 10. procrastinator won the regular. I won the declare-only.

2-ways: I beat NN by 3, lost to AA by 8.

Even though we’ve all seen CHO misdefend, and even though he defends the same at both tables, if everything has been the same up until the point of misdefense, both NN and I were expecting to lose lots of imps on this defensive debacle, same at both tables:

The heart suit (not trumps): Dummy 108. Declarer’s RHO: QJ65. Declarer: K743. Declarer’s LHO: A92. The play: 10 from dummy, small, small, A. If second hand covers the 10, declarer has no chance.

But NN and I had done nothing unusual in the bidding, and declarer would presumably play the same way under the same conditions, so why were we expecting to lose big on the debacle?

spoiler text

because he and I were second hand and failed to cover the 10. CHO, for a change, was not the source of the debacle.

While double dummy it can’t hurt to cover the 10, and was necessary here, when declarer has A and K, ducking forces him to decide on this trick whether to try a double finesse.

I reissued those 4 challenges. I haven’t played the 2-way against procrastinator yet, will reissue that one when we both have.

16

lost to procrastinator by 6. could have been much worse. Reissued

17

Lost to NN by 5 (7-2) in a match that saw no swings of more than 2 imps. Beat AA by 14 imps. I reissued both. I’ve finished both group challenges and the 2-way with procrastinator.

18

I win the 2-way bloodbath with procrastinator 31-24. Hand I’m most upset about was a push, as neither he nor I could believe what the system notes were saying about what a simple raise of partner’s overcall would mean. Or maybe he didn’t bother looking, since it was so obvious that we should raise. I did look, and raised anyway.

Challenge reissued.Screen Shot 2020-10-17 at 1.04.21 PM

19

I scored +34.75 in the regular group challenge. With such a high score, did I win by at least 10? No, I didn’t even win: procrastinator had +35.75. He also won the declare only with +14.50.

I reissued both.

Sneak preview: my 2-way against NN is not going well. I still have several boards to play, but on the played ones I’m just hoping he makes the same calls and plays I did, since there are few reasonable choices he could make that would turn out worse.

21

“Not going well” but in a different sense than I expected. Turns out it was correct if it means “I am not building up nearly enough of a lead for the debacle that is to follow.” I had played 7 boards then, and was actually up 4 imps. Sure enough, he had easily set a game I allowed to make. The other was just a part score, and was a push. Different misdefense (as the cards lie) but we both let it make when taking the best chance for a set would defeat it.

Then I totally fell apart, and ended up losing by 24, defending absymally against 2 game contracts. Perhaps CHO deserves some of the blame on the last hand, though it was within my power to defeat it. You’ll undoubtedly give me most of the blame.

We are defending 4 spades. He opened 1 diamond, I responded 1 heart, next hand overcalled 1S. He made a support double (exactly 3 hearts). They reach 4S. He wins the diamond K (dummy has a stiff) and shifts to the heart K, dummy holding Jx. Declarer wins the ace, and I have 6, so hearts must be 6-3-2-2, with partner holding KQx. Partner wins the ace of clubs at trick 3 and gives me a club ruff. We have book, and the heart Q is the setting trick. But when I lead a small heart, dummy’s J wins. Does CHO get 100% of the blame?

spoiler

No. My hearts were Qxxxxx. But I was so sure his K had to be from KQ, I forgot I had the Q. :duh:

After that disaster I was going to lose, but I threw away a 100% cold game on the last hand on a play that (at best) marginally improved the chances of on overtrick.

Thinking I had to be able to play better than that, I reissued the challenge.

Then, as I composed this message, I learned I won the challenge against AA by 2, so I reissued that one, too.

You might think “Declare only” is purely a play challenge. You would be wrong. I haven’t finished this one, but I just successfully figured out how to play a hand to make an overtrick. Will it be a pickup? No, partly because as the cards lie the other reasonable life of play leads to the overtrick, but more importantly

spoiler

Somehow I misclicked the claim screen while trying to claim the overtrick and conceded down 5.

22

I won both group challenges. Declare only with +7, despite going down 5 instead of making a partial with an overtrick due to misclicking on the claim screen. Regular with +29.25, a margin just over 10.

I reissued both.