riverwalk3

Usla seems set to overtake Leo LaSota within the next 2 months or so as the number 1 masterpoints. One of his strategies from observing his boards is to rebid 3NT after partner responds to 1 of a suit with 1 of another suit, even with a random 13 count and a balanced hand. I'm not sure why how this strategy is effective, but it has to be effective given usla's results.

It worked against humans in a silver lining week tournament: https://tinyurl.com/2hhmfokv

In this deal, my robot opponents bid to a slam off 3 keycards: https://tinyurl.com/25f95txj I knew from the 5NT followup and my own hand that they were probably missing 3 keycards (and thus my partner held an ace), so I doubled them even though they stopped in 6. All 3 keycards took a trick, so they went down 2. Note that East could still have 5 keycards from the bidding (all 5 keycards is 19 HCP, + singleton makes 21 total points, which is stil slightly too weak for opening 2 clubs. [hv=pc=n&s=sj974hk97da9cjt92&w=s62hqj8532d2ckq43&n=sat85hdjt865c8765&e=skq3hat64dkq743ca&d=w&v=n&b=12&a=pp1dp1hp4cp4np5hp5np6dp6hppdppp&p=c5cac2c4d4dad2d5s4s2sas3d6d3d9h5h3c6hthks7s6s5skh6h7h8s8h2c8hah9d7c9hjdjc3c7h4ctsqs9hqstckd8dqcjcqdtdk]399|300[/hv]. However, once East shows the diamond king, West signs off in 6 hearts because it's impossible for East to have all 5 keycards then (that would mean 22 HCP + singleton, which would probably open 2 clubs). If West still thought East had 5 keycards, this would warrant a 7 hearts bid (6 hearts, 3 clubs, 1 spade, 2 diamonds, 1 club ruff).

How would you find such a stopper, when both sides have partial stoppers that combine into a stopper? Does the person with Qx just take a chance (rightsiding the contract if partner has something like Kxx or Axx)?

From my understanding, a robot accepts a claim if there is a sequence of plays that gets at least as many tricks as claimed against any distribution (including ones inconsistent with the bidding). In yesterday's daylong tournament I played, a robot accepted a claim on a double squeeze. This is the link to the hand: https://www.bridgebase.com/tools/handviewer.html?lin=st||pn|riverwalk3,~Mwest,~Mnorth,~Meast|md|2SAQ63HK74DAT8CKT7,S94HT2DKJ97CJ9842,SKT8HAQJ5D3CAQ653,SJ752H9863DQ6542C|sv|o|rh||ah|Board%208|mb|P|mb|1C|an|Minor%20suit%20opening%20--%203+%20!C;%2011-21%20HCP;%2012-22%20total%20points|mb|P|mb|1S|an|One%20over%20one%20--%204+%20!S;%206+%20total%20points|mb|P|mb|2H|an|Opener%20reverse%20--%205+%20!C;%204+%20!H;%203-%20!S;%2021-%20HCP;%2018-22%20total%20points|mb|P|mb|6N|an|4+%20!S;%2017-19%20HCP|mb|P|mb|P|mb|P|pc|C4|pc|C3|pc|D2|pc|C7|pc|S3|pc|S4|pc|SK|pc|S7|pc|S8|pc|S5|pc|SA|pc|S9|pc|SQ|pc|D9|pc|ST|pc|S2|pc|HK|pc|H2|pc|H5|pc|H6|mc|13 At first it looked like an easy 13 tricks, but then East showed out on the first club lead. I won cheaply, then tested spades by leading 3 rounds when the Jack didn't drop, West showing out. I then lead the king of hearts then claimed 13 tricks to see if the robots would accept (not aware of the double squeeze yet), and it did. The robot accepted the claim because there was actually a double squeeze guaranteed once West showed out in spades (implying East was guarding spades), and East showed out in clubs (implying West was guarding clubs): run the hearts, forcing West down to 1 diamond to guard clubs, then cash the top clubs which squeezes East in spades and diamonds (since East discards before you). In fact, I could have claimed as soon as I won the club lead: If West instead guarded spades, then there would be a simple squeeze against West in spades and clubs. If East guarded spades, then there would be a double squeeze. Otherwise, if spades were 3-3, I could win 4 spades without any squeezes. I think the robots should be reprogrammed to accept any claim based on top tricks (with the cards played so far), rather than more complex plays, even if they are 100% lines. Even then though, I often abuse the claim function when I don't remember if a card is good or not and playing that card if not good is risky. Most humans don't accept the claims unless you state clearly how you would play it out, and I doubt any human would accept my claim in that deal unless in an expert match where the claimer clearly specified double squeeze.[hv=pc=n&s=saq63hk74dat8ckt7&w=s94ht2dkj97cj9842&n=skt8haqj5d3caq653&e=sj752h9863dq6542c&d=w&v=0&b=8&a=p1cp1sp2hp6nppp&p=c4c3d2c7s3s4sks7s8s5sas9sqd9sts2hkh2h5h6]399|300|13 tricks claimed, Score = 92.7%[/hv]

Currently, a lot of players earn tops in the Zenith Daylong tournament when they open (or overcall) 4NT nonvulnerable with a weak hand, and go down 6-8 tricks for a top board compared to the opponent's game. This is relatively safe if partner is a passed hand (which when combined with your weak hand indicates that the opponents probably have game). Will this ever be patched? (ie a robot doubles 4NT with a reasonably strong hand). Below is an example. In this case, LHO should clearly double.

Signals are often useful in defense as it gives partner useful information, but sometimes the information isn't too useful for partner and might instead help declarer. For example, if declarer has KQTx opposite Axx, declarer will probably first cash the King and Ace. Assuming the Jack doesn't drop), if declarer knows that the suit is breaking 4-2, then they will finesse the 10 next. In such a situation, it is better to not give an honest count signal to aid declarer. When should you give honest count signals? And how should you play if you don't want to give an honest signal? Just play a random spot card?

There are also a lot of zeroes out of your control: ie your opponent bids a thin game that nobody else does and every finesse is onside, or your opponent stops below game when everything else is in game and suit breaks turn out to be bad. Or your opponent finds a brilliant play that few others find.

I'm mainly thinking of an ACBL regional type event, where you get enormous amounts of masterpoints for getting an overall top (30+ in some cases), and very little otherwise. Additionally, a section top is the only way to make gold points. In this case, it's very hard to imagine someone good enough to consistently get first. Even stars often get scores below 60, from what I'm seeing, when first is usually at least 65. I'm already nearly good enough in robot tournaments to consistently get in the top 3 of my section in ACBL robot duplicates, and am pretty sure Leo LaSota is. In this case a high variance strategy might not be so good (but even then I see Leo LaSota open 1NT with unbalanced 13 counts for example).

I've seen advice to go with the field on the forums. However, isn't higher variance better for tournaments (with the same expected value)? For example, fluctuating between 45 and 65% is better than getting 55% every time, as you will get overall places some of the time with the former but never the latter, and will often get a section top with the former. Thus, it seems better to go against the field, if on expectation the actions are the same. In an extreme example, suppose you have a choice between having a cointoss between 0% and 100% every board, versus getting 50% on every board for sure. In 12 boards, if you choose the cointoss you will get 75% or above 7% of the time, and 67% or above 19% of the time. This means that you will get overall tops very often in this case, while you will barely get any masterpoints at all with the latter.

I have recently started playing 55% Robot Rebates as I know the field is usually very strong there and am trying to challenge myself (I'm not looking to make a profit, which I'm definitely not good enough to, and even players who have won NABC robot individual before such as zhenya_s are only around breakeven). My average probably has been around 52-53% in Robot Rebate (although the sample size is small so this is subject to variance), compared to 60-61% in ACBL Robot Duplicate. While the rebate is certainly harder, I'm not sure it's 8% (I think some of the difference is psychological as I made some weird bids I usually don't in ACBL duplicate). I would be interested in someone else's experience suggesting the difficulty difference. I've also noticed the Zenith Daylongs being much harder (I've broken 70% once as a fluke but often get below 50%), but a closer inspection could give a big part of the difference: I averaged 63% in contracts I declared compared to 47% overall today (and 53% declared yesterday versus 44% overall yesterday).

Suppose South Dealer 1NT P 3NT A, and the Xs are as small as possible.

The scoring is 1 if you get a strictly higher score than the other table (whether by 10 or 1000), 1/2 if you score the same, and 0 if you score strictly below. Hence the finesse would clearly be the normal play without considerations of being ahead/behind the other team.

In Board a Match, say you are in a normal contract and there is a risky play available. Ie suppose you are in 3NT with S xxx H Axx D xxx C AKQx opposite S AKxx H xx D AKJ C xxxx. West leads the King of Hearts. Assuming clubs split 3-2, this gives 9 top tricks. Once you lose the lead, the opponents will run hearts. You can finesse diamonds, but that would risk going down. However, it's probably still the correct play at matchpoints (after running clubs and possible forcing some uncomfortable discards), given that the opponents might only cash 3 more hearts anyway after losing the finesse. The question now becomes: what play should you make if you are currently ahead? Behind? For example, if you are behind, should not finesse, hoping the other team finesses and you get a swing?

Declarer usually outperforms double dummy at the game level, because the opening lead matters a lot and the double dummy defender always makes the correct opening lead. At the slam level, the opening lead matters less, so it is about a wash. At the grand slam level, the double dummy declarer always makes the right play, so the defenders usually outperform double dummy at the grand slam level. Also, in your "bad" examples where North had a lot of points in the red suits, he might bid 4NT instead of 4S, which discourages slam and shows strength in the unbid suits (as 4 clubs was a slam try since it commits the partnership beyond 3NT without assurance of a fit).