Bridge: Up for a challenge?

The Sandbox Games
183

I haven’t tried this, but it may well be a viable way to get double dummy analysis of BBO hands: Bridge Solver

Note that double dummy analysis only gives the best result you could achieve, on this full deal, assuming best defense. It doesn’t show what you should have done. Double dummy, if you can finesse either opponent for the trump queen, you will always finesse the right one. If the trump king is offside singleton, you will drop it, even if the odds are much better for finessing.

Usually I can tell after the hand what would have worked best, even if it is still unclear whether that’s how I should have played. Alas, in the current challenge against NN, I know I threw away a game I should have made, and know it was bad play. The successful line was far more likely to be right than what I did.

184

Sure enough, I lost 10 imps on that hand, but won the match 26-24. Reissued

185

That program worked. Thanks.

So it was hand 13 of our recent challenge. I bid to 7H (partially spurred by partner). Everyone else stopped at 6H and made it. I won’t be surprised to be told that 7H wasn’t sound. But it certainly had a chance, as seen by the cards.

When the cards flipped, I felt like we had a sure 13 tricks (I even tried to claim). But I was wrong in that we didn’t have enough tricks if we simply pulled trumps (which I figured out before trying to do so).

Based on double dummy, it looks like you needed to do a “dummy reversal” (I think). I guess one question I have is whether I should have been able to realize that when the cards flipped, or if that was just one of many potential outcomes / strategies based on our cards.

I got -17 on this as the only one who didn’t make 6H. If I make 7H, I think I get something like +10-+15, which is a ~30 point swing and takes me from last to first. :frowning:

186

If you look at the other tables, oirg and I made 7H. I would have made it if I were in it, but I played somewhat safe for 6 and the LHO misdefended. oirg made 7 with even less risk of going down in a makeable 6. He got a trump lead, won in dummy. He ruffed a club in dummy, then with trumps 3-2 and diamonds 4-2 (both as you would expect), he pulled the remaining trumps, ruffed 2 diamonds, setting up dummy’s 5th diamond for his 13th trick.

Another reasonable line in (best I think) is to ruff 2 clubs in dummy, needing diamonds at worst 4-2, spades at worst 4-3, clubs at worst 6-2, trumps at worst 4-1. Can also survive spades 5-2 if LHO has the 5 (and could survive spades 5-2 if RHO has the 5 and trumps are 3-2, but you’ll have to guess whether RHO has 2, 3 or 4 spades before knowing how trumps break, so you’ll likely play for RHO having at least 3). That’s how I started, slightly worried since I had a diamond lead which could have been stiff, but still with very good chance of 6 if it were a stiff diamond. But since I didn’t need 13 tricks, I played safe and took only one club ruff. Then, LHO unguarded his club Q (correct defense if my spades had been 10xx and his partner had the club J).

Neither successful line is a dummy reversal, though both have some elements of crossruff. A dummy reversal requires ruffing so many tricks in your own hand that you end up with fewer trumps than dummy, then use dummy’s remaining trumps to pull trumps.

Yes, had you made 7H that would be +13 imps for you. A swing of 30 points in your score, but also negative swing of about 6 or 7 to each other player, so an overall win for you.

Documenting the result: I won with +13.00, a margin of 8.25. Reissued.

187

Interesting. I’m not fully following on first read. But when I ran through the Bridge Solver, they used my hand to trump diamonds 2 or 3 times, then had dummy pull remaining trump, hence why I said dummy reversal.

In my quick reading of your lines, they don’t sound much different than my thinking. So where did my play fall short?

188

I don’t know what the Bridge Solver line was, but your description of it doesn’t really make sense to me. “Had dummy pull the remaining trump” (when one opponent has at least 3, in fact only 3) suggests that the third round of trumps was led from dummy, and that therefore none of dummy’s trumps were used to ruff clubs. Maybe that’s possible here, but would be done only as a double dummy exercise.

Especially in a grand slam, you should think about what 13 tricks you are going to take. Though neither oirg nor I needed 13 (nor did the others who perhaps played marginally safer for 12), here’s how I would count the 13 tricks I would have taken had I needed 13: 5 trump tricks in my hand (perhaps by leading them, perhaps by ruffing with them; perhaps some of those 5 will actually be won with dummy’s honors, but it’s definitely 5 tricks and no more won on tricks where a trump was played from my hand); 2 in diamonds, 2 in spades, 2 in clubs (with the AK of each). That’s 11. I need 2 more. My line gets them by ruffing 2 clubs in dummy. (Those are additional tricks, beyond the 5 tricks where a trump was played from my hand.)

oirg’s count of 13: 5 trumps in his hand (2 of which will be won by ruffing diamonds; some of the 5 may be won with dummy’s honors instead of declarer’s, but only 5 tricks that include one of declarer’s trumps), 2 in diamonds, 2 in spades, 2 in clubs (with AK of each). That’s 11. He needs two more. 1 with a club ruff in dummy. 1 with the last diamond (which is good after he ruffed 2 in his hand).

In both cases, you have to pay some attention to the order in which you try to take your tricks, but if you can’t come up with an idea of what 13 tricks you hope to take, your chances aren’t very good.

189

My plan was to get the two extra tricks by ruffing clubs in dummy. But I must have messed up the order, because opps were able to make their trumps good before I could pull them with my hand.

190

No, you defeated your own plan. After ruffing one club, you played two rounds of trumps, leaving you no trump in dummy for the second ruff. After the first ruff, you could have succeeded by leading a trump to your hand, the ruffing the last low club, then you just need to get back to your hand to pull trumps. Take AK of spades, then try to ruff a spade with the 8. When it wins, pull trumps and your hand is high.

(Though after that first ruff and two more rounds of trump, you could still have succeed with oirg’s approach. If you win both those rounds of trumps in dummy, you are in the right place to ruff a diamond, pull the last trump, return to a high spade to ruff a second diamond, then you have the club ace, a top spade, and the last diamond for the 13th trick.)

In writing that up, I realize that playing the way I suggest to ruff 2 clubs in dummy, you need hearts 3-2. In retrospect, I think you can play in a different order that would handle hearts 4-1, though it does still require you to be able to ruff the third spade with the 8 and not be overruffed. That’s very likely to work.

191

Win by 20 vs procrastinator in a match that I was afraid I had lost, despite LHO going down in 6NT he should have made easily. (I correctly guessed that would be a push, procrastinator’s LHO playing equally bizarrely. LHO, after first playing a low spade from xx toward dummy’s AQ10, and winning the 10, later decided to lead to the ace, rather than finessing.) Reissued.

Win by 12 vs AA. Reissued

ETA: I win the Declare-only with +20.25, by 6.75. Reissued

EATA: Lose 3-1 to NN. Every imp for one extra overtrick made or yielded. Reissued

192

procrastinator wins the regular challenge with +27.25, a margin of 21.25. Reissued

193

Looks like 12 IMPs came on a board where the RHO lost his mind. Had JTxx of trumps (diamonds) against a 72 fit, and split on the first round when there was no reason for me to take deep finesse. Double dummy based play leads to some crazy plays…

194

I win by 8 vs AA. Reissued

ETA: I win by 31 vs procrastinator. Reissued.

EATA: I lose by 3 to NN. Reissued

195

Oops. Regular challenge is in progress, but will go until time expires, with maximum 4 of us playing. I mistyped NN’s BBO username. If I do that in a 2-way challenge, it stops me, but apparently not in a group challenge.

196

Totally baffled. I thought there was a Declare-only challenge in progress. Maybe there was and it ended yesterday. I see there is one listed as 2-10-2021 that I haven’t reported on. procrastinator won it with +14.25, a margin of 5.75. If the date means it started 2-10, then I didn’t miss one. Regardless, I just reissued a challenge.

197

oirg wins the regular challenge, to which NN was by mistake not invited, with +15.34, a margin of 3.35. Reissued

Win vs procrastinator 12-1, with my 12 all coming from an extremely friendly defense against my 4S contract. Reissued

ETA: Lost to NN by 2-0. 1 on an opening lead against a slam, where I gave up an overtrick. The other where I was safely in 2S, making (with a heart finesse available for making an overtrick or down 1, so I didn’t take it.) He was in 3S (with a heart finesse available for making or down 2, so he took it, and it worked). Against 3S, his RHO could have set him for sure (as the cards lie) with a different defense, likely but possibly not the best line of defense. Reissued.

EATA: Win vs AA by 9. Reissued

198

oops. Both group challenges are regular, no Declare-only. c’est la vie

199

SW1 wins his group challenge with +18.75, by 3. NN wins SW49’s group challenge with +15.25, by 5.75.

I’m slightly surprised to lose the regular challenge to procrastinator by 5, since I passed in 2S rather than try for game, vulnerable. On our hands, 4S would have been a very reasonable contract, under 50% but close if not above the odds necessary for a vul game. Lie was terrible, and 2S was the limit. Procrastinaor also stopped in 2S.

In the same challenge, we had this challenging hand: S-AQx H-AQJ9 D-Kx C-K10xx. Partner opens 1S in second seat, unfavorable vul. You elect to bid 2C, and your RHO, a passed hand, calls 2D. CHO raises to 3C. You show your spade support with 3S. CHO bids 4S. What do you bid with a trusted partner? With a bot?

Maybe procrastinator found the best call: 6C, likely the best spot at imps if partner does have 4 clubs (as system notes says he should, though with a human partner I wouldn’t think that’s guaranteed).

I instead chose to invite a slam, and wanted to focus on whether partner had second round diamond control, since with the overcall I thought I didn’t. How? System notes weren’t clear. I think 5S probably asks for a second-round diamond control, but notes didn’t suggest that, so I cue bid 5H (at least denying either minor suit ace). Partner jumped to 6S. An absolutely awful contract, on the bidding, since he had xxx of diamonds. But the lead was the diamond ace! (and since it was onside, the contract would have made regardless).

Meanwhile procrastinator hadn’t even protected his diamond K, since his partner converted to 6S. Push.

All three reissued, this time with SW49’s group challenge as Declare-only.

200

CHO converting 6C to 6S irked me. No diamond lead at my table, and I played it some convoluted way to make just to find out the ace was om…

But worse was the bidding on board 4. CHO had AJT983 J32 J2 Q5, and saw the auction start on his right:

(4C) P (4D)* 4S * cue for clubs
(P) P (5C) P
(P) ?

Partner has bid spades at the 4 level, and you have 6(!) card support, and he … passed
Nuts. Also, please do not look at my hand for the 4S overcall…it was not sound.

201

Lost to NN by 29. It should have been worse. Reissued.

ETA: win by 14 vs AA. Reissued

202

Lose to procrastinator by 13. Not surprised by the result. Reissued.