[giorgis_di]

helene_t, on 2024-May-12, 12:35, said:

From tomorrow, DavidKok and I will start playing Cottontail Club in a local teams tournament. We will keep you posted

It's a quite aggressive system in that we open 1M freely on a 4-card suit, both with balanced 11-13 hands and with canape hands. And with 5♣332 11-13 we open 2♣ (which includes 10-15 with six clubs also).

Lorenzo is a system that used to enjoy some popularity in the Netherlands. All 2-openings are 0-7 points with 4+ in the suit (some play 2♣ as an unknown minor and 2♦ multi but that's a BSC). They pass with most 8-11 hands.

Fantunes is quite aggressive also, not quite as aggressive as EHAA but quite similar. It may have lost some appeal after it transpired that Fantunes's success was not exclusively due to their superior bidding system ...

Among normal bidding systems, English Acol is fairly aggressive, opening 12-14 NT and with 15-19 balanced they open a 4-card major if they have one.

The least aggressive system which has been played in living memory may be Vienna, in which all 2-openings are strong, 1NT strong and artificial, 1♣ covers all normal openings without a 5-card d/h/s. Among modern systems, SEF is the least aggressive I can think of. Similar to SA except that 2♦ is strong and artificial.

Could you share a link (or something similar) where I can find more details on that system?

[DavidKok]

It is discussed in more detail in https://www.bridgeba...394-kok-canape/. The system is based on Cottontail, but I have renamed it for two reasons:

• I have made so many changes to Cottontail that only the openings are still somewhat similar (though not identical), though I feel that I stuck to the philosophy of the original system as best I could.
  
• People commented that they thought I was trying to steal credit from Jan Eric Larsson, or present my own ideas as if they were validated by him. This is not my intention.

[awm]

Out of curiousity, how has the teams tournament been going? Any spectacular wins or losses for the system yet?

[DavidKok]

We've had a number of spectacular wins, though quite a few of them due to opponents' mistakes rather than our brilliance. I find it hard to draw the dividing line between those - the system is designed to put on lots of pressure, so some amount of errors will be 'induced' by us, but it feels weird to take credit for any individual poor decision. An example from last night (deal rotated to make me South):

---

Keep in mind partner does not have a 4cM and unless partner has the diamonds-hearts canapé (in which case the opps can play in clubs or spades) opps have 8(+) combined hearts - in conclusion, they always have an 8+ card fit. Therefore the system bid with my hand is a preemptive 3♦ raise, showing approximately 4-9 HCP and 4(+)♦.
3♥ went for an easy +1, game was cold as the cards lie. Unfortunately our teammates failed to bid the game so no swing, though there would possibly have been one had we been less aggressive.

As an example of a possibly spectacular loss (rotated to make me South):

---

As the cards lie 3NT by East is cold, 4♠ by either hand is cold, but 3NT by West can be beaten on a diamond lead. However, there is no way for partner to read this, so the contract made comfortably. The opponents assured me if I'd shown diamonds they would have had East declare it, but that's easy to say after the fact. The end result is kind of unimpressive, 3NT+2 loses 2 IMPs to the field average, but the potential for a big swing was here and the canapé style possibly ended up costing.

We've been practicing on CueBids, so far it's going great.
https://imgur.com/in79R34
We do have a number of growing pains from getting to know each other's styles a bit more and agreeing on tools and gadgets as we go, so I expect this star number to go up to ~2.70 or so once we iron that out.

Lastly we've played three evenings so far at the local club - twice in the competition, once in a spare evening. So far we've scored +28 IMPs and +2 IMPs in the competition (24 boards each) and +49,4 xIMPs (crossIMPs) on the casual evening (24 boards). There were a few rare but costly system misunderstandings, but by and large it's been smooth sailing. I feel like we are frequently getting to good contracts and keeping the opponents' out of their best contracts, but we lose a bit on card play. As a practical matter: our team is placed 5/16, so we're advancing to the top bracket of the knockout phase.

Personally I feel like the system is extremely comfortable. I can draw a ton of inferences that would not be available to me in standard, and I seem to always have the right tools for the situation. I've been correctly making strange calls that would normally not occur to me, simply because I have so much more information on (competitive) auctions. We've also had a number of "blast game" auctions that really put the opponents to a guess. The four known weakness hand types of Kok Canapé are rare, we've had two so far, and they usually don't lose when they do come up (and haven't so far). All things considered I'd say it's going amazingly well.

[helene_t]

Another good one was the auction (white against red, playing against someone from the Dutch national junior selection):

1♥-(2♣)-4♥-(p)
pass-(5♣)-x-a.p.

Here, responder had a 2542 14-counts, the 4-card 1♥ opening in combination with the limited opening put pressure on opps. +500 plus -420 so not a great swing, and of course if it had been opener who had five and responder who had four, canape would have worked against us. Including balanced hands with a 4-card major as well as M/♣ with 5-4 either way in the 1M openings allow us to find our fit relatively often, but of course sometimes responder can't put quite as much pressure on opps as they would have if 1M had promised an unbalanced hand and/or promised a 5-card.

The strong club opening also gained on some hands where opps bid too aggressively against it.

On the other hand, we missed one good slam when opener had a prime 3532 13-count and it went
1♥-2♣
2NT-?
and it might have been easier if opener had shown a 5-card suit.

We also (on cuebids, not in real life so far) lose on some of the strong 1♣ auctions were we have too crude agreements (Meckwell Lite) about follow ups. We deliberately decided not to give that a high priority because it doesn't come up that often, and on most hands you can reach the right contract even with crude agreements, but at some point we should work that out in more details.

There we a couple of hands where the problem was that I don't understand canape well enough. Once I passed
1♦-(1♠)-3NT
despite holding a six-card hearts, and that was not a great choice. David explained afterwards that in that situation I should always bid a major canape suit.

Another auctions was
1♥-(x)-1♠-(p)
1NT-(p)-p-(x)
p-(p)-2♣ a.p.

where I (responder) made the (probably mistaken) decision to pre-rescue from 1♥ in case my LHO had long hearts. Opps were friendly not to double and make a defensive mistake so it was only -50 but could have been expensive.

Overall I think the biggest gain from the system is that it is relatively easy to play (considering how little experience we have as a partnership), leaving some brain cells alive for the defensive bidding and the card play.

[thepossum]

hrothgar, on 2024-May-15, 06:43, said:

There are a host of competing considerations, above and beyond reaching the "best" contract (whatever that may be)

Memory load is one very important consideration
Minimizing how much information you leak during the auction is another

Ultimately, bidding systems are designed to score well in the aggregate / across many boards.

This is not the same reaching the par contract on every board.

All I was trying to say was the system should be capable of (EDIT reasonably) accurate bidding even when opponents give no information at all

Like walking into a business meeting and giving a perfect sales presentation with no interference

Sorry we overreached, we had no competition

[awm]

Thanks for the examples; they are interesting to read!

It's probably going to be hard to evaluate a method where the primary goal is to preempt on more/different hands than the field, because the main benefit is that you give the opponents more difficult decisions than your teammates face at the other table. Sometimes the opponents will get the decisions right (and/or your teammates will get the decisions wrong) so any given hand is unlikely to prove anything. And the IMP totals don't tell us much about the system because we don't have a good baseline (for example play and defence have a big impact on IMP totals too).

Maybe over a large set of hands you could measure the frequency with which your opponents miss a very good game/slam (or overbid to a no-play game/slam) and compare it against the field overall? It might be difficult to do this analysis though, depending on how much data is kept over time.

[DavidKok]

I don't think 'preempting more' is the primary goal of the system. Rather it is 'to gain as much advantage as possible on the (anticipated) competitive auction'. To this end we employ a strong club with moderately aggressive (open 'all' 11-counts) limited openings, a sound notrump ladder and no nebulous bid (well, 1♦ can be 3 on 3=3=3=4). The mildly preemptive effect of the 1♥ and 1♠ openings is great but not the main goal of the system, rather this is a consequence of the rest of the design.

We are still practicing and learning, possibly also adapting the system a bit as we go. At the moment I am not interested in keeping some kind of track record, I only provided it because our results are readily available on the club website and you asked for them directly. It's also not that easy to split play and defence from system - the difference in information shared has a definite impact on the play (most extreme - when the opponents have almost no distributional information on a 1M-4M auction).

To me what matters a lot is that I feel we have great freedom and excellent tools on all hands we play, with only very rare guesses or problem hands. Precisely on the 2-over-2, 3-over-2 and 3-over-3 decisions Kok Canapé has shared all the relevant information early, and we can often get these right before the opponents even know that this is the critical decision on the deal.

[helene_t]

One thing I like about the system is is that when responding to the 1♦ and 2♣ opening, responder can bid notrumps with or without a 4-card major, making the defense more difficult.