stair step to a higher level pageConstraint Files for Bridge Base Online


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Bridgebase Online allows us to form a "bidding table" where zero to three of the players at the table will be robots (See GIB). The auction transpires, but the resulting contract is not played out— excellent for bidding practice.

One option when sitting at a bidding table is to press the "Deal Source" button where you will see a series of tabbed windows. There, specific bidding constraints can be entered for the hands BBO will deal. The "Advanced" tab leads to the most powerful feature: the ability to enter constraints in a programmer-like language. Through this, you can specify very tightly how BBO will deal the cards in a way that lends itself to practicing a given convention or situation. The links in the table below lead to constraint files I have used.

To use a constraint file, click one of the links below and copy the file (text only). Be sure to copy the entire thing, parentheses and all; they matter. You may save it to your own machine or just paste it into the BBO bidding table's advanced tab. Before you leave the "advanced" tab, be sure you check "Use this input for the Dealer program." If you forget to check this box, the content you just pasted won't be used.

The robots you bid against can be made silent or noisy. When you create a BBO bidding table, check the radio button labelled "Opponent's Bidding" "Controlled by Host". This will cause the BBO robot players to bid their hands per the GIB schema rather than being silent throughout.

Important: Switcheroo. You and partner may be confident that you can handle every combination of hands that might respond to a one notrump opener, but are you just as confident that you could handle the same 26 cards if the opposite hand were the dealer (in other words, the responding hand is the balanced 15-17)? This is the sort of thing switcheroo forces you to check. Don't be surprised when BBO makes the "wrong" hand the dealer.

P.S. #1. The Deal Source feature can also be used at BBO's Teaching Tables.

Table of Constraints

File Name Description or Challenge Pub Date (yyyy,mm,dd)
Overcall 1NT with a singleton As of Feb 2020, ACBL rules allow us to have a singleton in our 1NT overcall or opener when we lay claim to it being "Natural" only when the stiff is an ace, king or queen. If the singleton can be a lower card, the hand doesn't fit the official definition of Natural. If it's not Natural, it's Artificial and consequently, would need to be alerted.

Because your singleton changes the makeup of the other three hands, this constraint may help you choose whether to go Natural or Artificial.

ALERT: To test only overcalls, uncheck the BBO boxes that let North and South deal.

Versus Multi-2 Click this reference for methods one can use versus the so-called Multi-2 convention. It's popular in Europe, but not the USA. So those who need to defend against it at top level US tournaments may need the practice.

ALERT 1: You will not be able to use BBO's robots with this constraint since the robots don't know this convention. Best to have human opponents.

ALERT 2: To get the best effect, uncheck the boxes that let North and South deal.

Click this reference for details. This constraint covers only opener's mini-splinter, not responder's.

Summary: Sometimes, after opener bids one of a minor and responder bids one of a major, the opener's hand, in support of responder's major, will be worth much more as long as responder's hand contains little or no duplication of value. The ability to reveal this value provisionally can prevent doomed games and also allow the envisioning of magical slams.
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Update of 2021-03-28 also deals the strong jump shift hands that a mini-splinter displaces. Test your alternative choices.


Orig: 2019‑09‑11

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added separate Super Accept constraint.
All hands that need to respond to a 15-17 NT opener.
Includes the following switches:
1. to change the notrump range,
2. to force the NT opener to have a 5-card major,
3. to disinclude any given type of responding hand.
4. New for 2019: switch added to practice Smolen-ish hands.
See the documentation within the constraint file itself for details.
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Practice your version of Super Accept using the second link on the left.
See the comments in the constraint code describing the updates and how to use them.

Orig: 2010‑01‑21
Rule Of 2020 A nod to the current year: the Rule of 20 times two.
In theory, it takes an opening hand facing an opening hand to yield a game complement. So if the Rule of 20 yields a hand worth opening, then two such hands facing each other should yield a game often enough — terrible misfits being the obvious exception.
This constraint deals both North and South hands equaling exactly 20 under the rule.
• Read the original Rule of 20 in Points Schmoints.
• Then see whether your tweaks align with Larry Cohen's.
• Also baked in: the July 2020 advice Charles received from Marty Bergen via e-mail, referring to the 7222 hand pattern, "OK to count 2‑card suit as 2nd longest."
drury.txt Over partner's perhaps-light 3rd seat one-of-a-major opening, how do you respond and continue?

Be sure to check out the switches within the code designed to induce shortness in either hand — something that may result in upgrades, downgrades and splinter bids by either partner.
Complete rewrite 2020‑07‑04;
orig: 2010‑01‑21
Overcalling and Advancing Read a tutorial on this topic at BridgeBears.
ALERT: To make this constraint work properly on BBO, uncheck the boxes that allow North-South to deal.
Strong Two‑Suiters Professionals are divided on how to handle very strong two-suiters. Some won't open two clubs, some will. Using this code, you and partner can better choose your path. 2020‑02‑09
Puppet Stayman Many play Puppet Stayman over 2NT — a few even over 1NT. Test your methods with this constraint. Note: If wish to change the options in the code, read the instruction at the top of the code file.

For those just starting out on Puppet, see Puppet at Wikipedia.
Escape 1NT Doubled There are any number of escape sequences to remove 1NTX to a low level suit contract. Test yours with this constraint. New: If you use a different NT opener, change the vMin and vMax variables in the code.

Also, if you are not one of the many who follow Richard Pavlicek's "Aces and Tens" regimen to upgrade 14+ to 15, just skip those hands since they will be included in these deals. For details on the method, see Aces and Tens.

Click this reference for details. This constraint covers only responder's mini-splinter, not opener's.

Summary: Sometimes, over partner's one-of-a-major opening, a responder will hold a provisional limit raise hand whose valuation depends on shortness in an auxiliary suit. If so, responder can inform the opener of his shortness. This can induce opener to downgrade for duplication of value and avoid doomed game contracts.

Reverses For many beginning players, one of the more confusing concepts in bidding is the "Reverse." This concept has stood the test of time and can be found in books as far back as the 1930's (Culbertson). Practice them with this constraint.

Hint: Some of the hands this constraint deals will not be strong enough for a reverse.

Culbertson, Eli. Contract Bridge Complete; The New Gold Book of Bidding and Play. J.G. Winston Company. 1938. p. 214.
Advance Sacrifice Are you brave enough to leap to five in a suit in which partner has preempted? Are you good enough to quickly calculate what the opponents are making and also notice the vulnerability? 2018‑08‑31
Shortness Showing Showing shortness in the non-trump suit (or asking for it) allows us to diagnose Duplication of Value and revise our hand value accordingly. This constraint deals such hands.
• On 9/20/2016, added the option to turn on a switch that forces a singleton ace or king to reveal that this too can indicate Duplication.
• On 1/13/2018, added singleton queens and jacks.
Updated 2018‑01‑13,
Orig: 2016‑08‑25
3NT after partner's preempt Partner preempts 3 of a minor and you are looking at 19-21 HCP in a somewhat balanced hand. Do you dare convert to 3NT? The hands dealt by this constraint reveal how much you need to know your partner. What suit quality can you expect? What chance of an entry? 2017‑08‑29
Penalty Pass Partner opens and gets overcalled. Shall you penalize? Or compete? How? 2017‑08‑13
Bizzaro! Bizarre, one-suited hands don't come up often, making them tough to handle. Practice them with this.

Also, see the constraint file comments on switches that change suit lengths.
updated 2017‑08‑01
orig 2012‑05‑12
Lebensohl Over Weak Twos Deals hands for those who want to master using the Lebensohl convention versus opponents who open the auction with weak two bid.

See for example Lebensohl at Wikipedia.
Walsh Rebids For genuine Two-Over-One players, a one diamond response to opener's one club "denies ... a four card major suit unless [responder] has at least five diamonds and the values of an opening hand." (Hardy) Notice the advantages of this concept with this constraint.

Hardy, Max. Two Over One Game Forcing - Revised. Louisville: Devyn, 1989. Print. p.45
Slam Cues Can you and partner diagnose when it is that you have the general values for a slam but have two off the top in some side suit?

This constraint file contains a switch, aptly named theSwitch. On line 6 of the file, theSwitch=0 forces both partners to have the same uncontrolled suit; change it to a 1 (the digit one) when you want just one partner or the other to have one.
Slammish Long Minor Common problem: Partner opened a strong NT and you are staring at a one-suited club or diamond hand that may find a slam complement in partner's hand. How do you proceed? Also check out MSR 2015‑12‑16
2 Club Opener Derailed You wanted to open 2 clubs (Game Forcing), but the opponents open first. How do you recover? 2015‑11‑22
Niemeijer Partner opens 2NT. Can you handle all the continuations? One such method is found at Niemeijer 2015‑07‑21
Their 2-suiter Partner opens and the opponents chime in with some two-suited convention. Can you diagnose the continuations and get to the right spot? 2015‑06‑15
Awkward Super Minor A common problem: you hold 19 - 21 HCP, one long minor suit, and need an effective second call. Test your system and your knowledge. 2015‑04‑05
1NT Forcing The Forcing Notrump is widely acknowledged to be the weak sister of the 2/1 system. Thus the need to master it (with this constraint file). 2014‑12‑06
Forcing Pass Rule: If you and I as partners constructively bid a game, and the opponents press on, the *very* first pass by our side is absolutely unconditionally forcing for one round. The forcing passer's partner is forbidden from passing: he must either double for penalty or "take the push" and bid one more. 2014‑09‑04
Ingberman See Simon's Conventions for details. 2014‑06‑09
2- and 3-Way Game Try See the file's internal comments for Web links explaining this topic. 2013‑11‑24
New Minor Forcing
rarer ones
Is it a New Minor Forcing hand or just a one-off? The second file generates New Minor Forcing hands that occur more rarely allowing us to skip the more common ones that the first file generates so many of. 2012‑12‑17 and 2016‑01‑26
Namyats If you want to play Namyats, better practice with this constraint before springing it on partner in a real game. 2012‑04‑18
Game Force Whether it's a game-force opener or just a wannabe, can you reach the best spot? And what if the stronger hand isn't the dealer? Or worse, what if partner is a preempting hand!? 2012‑03‑18
Three-Suiters The 3-suited hand can be a magical fit or a maddening mess, especially when deciding between penalizing, pushing, and slamming. See how well you and your partner deal with them. 2012‑01‑10
Massive Whether a massive fit or a massive misfit, is it game, slam or just a part score? Can you handle the slam controls (including voids)? And how about duplication? For this one, be sure you turn on "Opponent's Bidding" "Controlled By Host" to see whether you can also handle the interference. 2011‑02‑13
Jordan A river of Jordan hands. And can you navigate the minors as well? 2011‑02‑09
Smolen-ish Is it Smolen or a wannabe? How often does your system get to the optimum contract and right‑side it? 2011-01-14
MajorsB.txt More of those majors. How do you handle these? 2010‑08‑30
Majors.txt You have the major(s). Now what? Game? Slam? Backing into NT? 2010‑08‑05
Their1NT.txt When "they" have a strong 1NT opener: can you steal the auction? Is there a game your way? Understand partner's continuations? Test it all with this. 2010‑06‑01
4SGF.txt 4th Suit Forcing? New Minor Forcing? And what then? Some hands are rather nice, but also rather awkward to bid. 2010‑05‑13
WeakTwos.txt Is it a Weak 2 or 1 of a suit? What if you aren't the first one to bid (overcall or jump)? How does partner continue? 2010‑03‑13
CrissCrossOrOther Respond with CrissCross, Inverted Minor or some other treatment over a one club or one diamond opening. 2010‑01‑21
1NT_Rubensohl.txt What do your bids mean when the opponent's interfere with your 1NT auction? 2010‑01‑21

Last updated: Sep 16, 2021 18:21 UTC-7