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This is a great service. Thanks to all team members at bridgewinners.com.
A couple years back there was a reception at summer NABC for BBO players. Is there any possibilities to organize a bridgewinners member reception at Providence? There are a lot of good discussions about bridge in this forum. It would be good to meet people in person.
Nov. 8, 2014
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No. I have two formulas. One for MP rating and the other for IMP rating. A game could be rated for MP only, IMP only or both. It is similar to chess where it has regular rating and quick rating. The difference here is that MP and IMP game needs difference strategies so they may need to be rated separately. One could not simply covert MP game result into IMP game result or vice verse.

The rating calculation only depends the game results and the pair's rating. It does not depend on population. For example in a team game, one team has a pair rating 2500 and the other 2300, the second team has a pair 2000 and 1900. The 2500 is playing against 2000 and 2300 is against 1900. Let's assume for a rating difference of 400 the stronger pair suppose to win an average of 1 IMP per board. So I could calculate and get 2500 against 2000 expected to win 1.2 IMP per board, 2300 against 1900 should win 1 IMP per board. So in this particular match-up, the strong team is expected to win 2.2 IMP per board. If you switch the match-up the expected score could be different. The game results are compared against this expected score and if the strong team win more than their expected score, their rating increase, if it is less, they lose rating. The same is true for the weak team so they just need to not to lose more than 2.2 IMP per board to gain rating. Please note the numbers are hypothetical. The real number needs come from tournament data to determine what score difference is appropriate for a rating difference.

The pair game is similar except one board could be played by a lot of pairs. So this one calculation is done for every pair on that board. Here the population is a factor because the more a board is played it get calculated more. So these board will have more weight comparing with those boards that played only by 2 or 3 pairs. In my calculation the weight increase is not linear so that one bad/lucky board will not skew the rating.
Nov. 7, 2014
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Peg, there was a separate thread about bridge rating recently and I have discussed my idea.

You are absolutely correct that bridge is a partnership game so the rating need to be on partnership not on individual. This is one of the key difference of my system from others (OKB or Power Rating). The other difference is that I used per board result and compared with every pairs who played that board rather than a single session result of percentage in MP game.

My test on a local club for two month's games generated 156 players and 128 different partnership. Each of partnership get its rating. For entire ACBL universe, it is going to be huge. However the modern computer technology is capable to handle it.
Nov. 7, 2014
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Peg, I think the technical difficulties are easy to solve as long as there is a need. I have developed an rating system similar to chess Elo rating recently. It is still in the early stage and I just tested with some local club game data I got from a director. I'm going to be in Providence and I'd be happy to show it to you and any others who are interested.
Nov. 7, 2014
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I think a better solution is a proper rating system that really measure player's ability. When weak team plays against strong team, they could still gain rating even they lose the game by a small margin. The strong team still win the match and go on. Everyone get something from the match.
Nov. 7, 2014
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The exact words are “An opening suit bid or response”.
Nov. 3, 2014
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I'm not sure this would work. What you quoted convention definition is item 5. However item 1 defines the following:

An opening suit bid or response is considered natural if in a minor it shows three or more cards in that suit and in a major it shows four or more cards in that suit.

So 1/ response needs to have 4 cards to be considered natural. Now do we have a bid that is not natural and not conventional?
Nov. 3, 2014
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Your last point is very good. I think it is very likely a lot of chess players would pick up bridge given a chance. I mentioned I ran a local chess club a few years ago. When the best player from my club went to high school, he has expressed interest in taking bridge lesson. There were a couple local bridge players offered lessons in that school. However they stopped offer lesson after that. So when I checked with him a year ago his school did not have bridge lessons. I also had another chess player who just played average and quit chess a couple years later. However he picks up bridge now and played very well. Recently he won at a 299er sectional with another youth player. This is mainly because his father, a bridge player who taught him and played with him.
I would recommend that any interested person to go to a local scholastic chess tournaments to see how to attract kids to a game. Bridge is certainly more complicated than chess and needs partnership. Kids could play chess from 5-6 years old. Bridge is probably better to start with Junior High. However they are both mind games and there are a lot of similarities.
Nov. 2, 2014
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I think ACBL's Junior/Youth program needs to be balanced in supporting top players as well as developing more young players. For this purpose I'd like to compare it with Scholastic program from US Chess Federation. Chess is very popular (at least compare with bridge) in school. Most states have two Chess Championship every year for K-12 kids run by local chess organizations. There are also two national Championship (Spring and Fall) run by USCF. Every four years there is a Supernational that draws over 5000 players. In addition there are a lot of other tournaments throughout the year. Here is a link to a tournament this weekend near Chicago.
http://www.polgarworldopen.com/

I have tried to get my son to play bridge when he was in high school. I even took him to play a sectional tournament and get a couple silver points. That is about all he did. He never played again. When I asked him why he did not want to play, he said none of his friends play it, he did not want to play a game with old people. My conclusion is there needs to be a critical mass if this game is going to take its root in youth.

Now let's look at what players are doing. In chess master players go to elementary school to offer chess lessons (as after school program). It is not free, in my local school they charge \$80-\$90 per student for an one month class. My younger son learnt chess this way. Then they organize local tournaments. Chess Grandmasters makes their living (at least a considerable amount of income) by giving private lessons to young players. In bridge, our professionals make living by playing with clients who could pay for it. So what chess master doing (their job) is to develop young players. Once their students are successful it draws more students to them.

The second issue about attracting young player is the reward structure. As you could see from above web site for chess tournament, the winner could get a college scholarship. Other prized include chess books, DVD and equipment (clock). All tournaments give a lot of trophies. In nationals all grade K players get a trophy. For players who could not get trophies there is chess rating. I ran a local chess club a few year ago. Every time I had an rated tournament, the participants would double, even though I do not give any trophies. Young players are eager to see how their rating changes after each tournament. It is a tangible measurement of their progress. The chess rating is different from bridge master point. It really measures players' ability. A young player who is talented could become a master at young age. See the following link:
http://en.wikipedia.org/wiki/Awonder_Liang
I happen to know this player. He played with my son in a tournament when he first started chess and they frequently met in local area tournament. In bridge our reward is master points. It is only given to a few winners and the rest get nothing. It would take a lot of time and money to accumulate master points.

The third issue is the rule of the game. Chess rule is very simple. It does not prohibit what player could play. For example you would play any opening you want. There is no regulation that you have to play King pawn open or Queen pawn open. The game developed itself. Bad opening that does not work get abandoned by players themselves. In bridge we tried regulate every conventions that could be played. Before you play your first tournament you must learn a lot of rules about what you cannot do.

I met a group of youth players from China at Philly's national two years ago. Their coach happened to be my classmates in high school where we learnt play bridge together. He told me he taught bridge lessons in Junior High and High School. He just went to school and persuade principals that bridge is a good activity for students and get their support to offer bridge classes. This trip to World Youth Championship are all paid by parents. He had to find travel agency himself to make logistic arrangement. China used to be a country where government control and sponsor all sport activities. It is very interesting to see that bridge becomes a kind a private enterprise now. Although I fully agree we need to support junior/youth players, I don't think we should do the old USSR/China way that only a few elite players get supported. We need some program to bring in more young players.
Nov. 2, 2014
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In just published BOD motion for Providence, there is an item to stop current new development for ACBLscore and have an independent review. See the following link.
Oct. 31, 2014
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In addition to default I'd suggest a capability of customized template. Most club almost always run one or two types of games, they could just load the template and have the information like director name etc. automatically loaded. As of number of table and movement, they could be calculated once pairs are entered. There might be a couple of possible movement options and the program could make suggestion and give options for director to decide.
Oct. 30, 2014
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Do we know how much is the annual budget ACBL spent on IT? If the decision is to keep developing ACBLscore, how much they plan to spend?
Oct. 24, 2014
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5 and 3NT by North with West holding AQJ9.
Oct. 7, 2014
Ping Hu edited this comment Oct. 7, 2014
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Alan, I think simulation might be a good solution but it might not be very practical. If this pairing program is going to be running on a server, it is not a problem. In practice it is going to be on a TD's laptop and it is probably running multiple events (different flights). So running a Monte Carlo simulation may not be feasible.
I think a better way is to get most updated game results from Bridgemate. For most unfinished matches, they should be on the last board. Bridgemate should have all other game results and you could make a very good guess of what match results should be (unless there is big swing on last board). Even you are off by 1 or 2 VP if may not make any differences in pairing results. Of course you could still apply your simulation for these last board results but is would be more manageable.
Oct. 6, 2014
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Nick, I see your point. It means there would be not table changes from round to round. Every team is stationary. It would also work when you assign next round before other teams finish because the teams finished already had their table empty. This saves the time players spent to look for their tables every round. It just gives caddies a little more work if it is not using pre-duplicated boards.
Oct. 3, 2014
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That's called inflation.
Oct. 3, 2014
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Jeff, based on the description in ACBLscore manual about “Matching Tolerance”, the field is not divided in half but a gradual scale determined by the parameters director set up. In the example it gives, the top team has a value of 0% and bottom team has a value of 20% to 80% (default) based number of rounds. This has an effect of given top teams better pairing than bottom teams. The bottom team has a much greater chance to be paired against a higher scored team (up to 16 VP difference) especially when it gets to later rounds.
Oct. 2, 2014
Ping Hu edited this comment Oct. 2, 2014
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The following is from ACBL Tech file CoC for Swiss team. You could also find information about Swiss pairing algorithm from ACBLscore manual section 3.20.5.5.

PAIRING

1. For the first match of the event, entries will be sold by random

draw (The sponsoring organization may elect to seed the first

match.*). If teams remain without opponents at game time these

teams will be matched as follows: the team with the highest team

number will be reassigned to play the team with the lowest team

number and so on as necessary. When only one such team remains,

that team will play in a three-way match including the two teams

with the nearest team numbers. * This includes, for the first

match, pairing A strat vs A strat, etc. as possible.

2. For each subsequent match, pairings will be assigned (within

groups of teams) such that: a) no two teams shall meet twice in

the event, and, b) 1. each team shall meet a team whose current

record is as close to its own as possible, or 2. for an event with

an even number of entries ONLY (i.e., no three-way matches):

randomly pair teams for their second round match. For the

remainder of the first session or one-half the total number

matches (rounded down)each team shall meet a team whose record

after the previous match is as close to its own as possible.

Current record must be used for the final session or for the last

one-half of the total number of matches (rounded up).

3. If only one team is leading, random draw shall determine which of

its equally eligible opponents it meets. With teams tied for the

lead, pairings shall be such that as many of the tied teams play

each other as possible. This procedure shall be repeated for all

teams still eligible to finish in the overall ranking.

Oct. 2, 2014
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Thanks, Jeff. This confirmed my guess that ACBLscore twisted the criteria of “equal score” to speed up the pairing.
Oct. 2, 2014
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Nicolas, since you are making your own Bridgescore+ now and not bound by any requirement from ACBL, why not just build a best Swiss team program using current technology rather than worry about ACBLscore? I think the best solution is to integrate with Bridgemate or at least getting per board result from Bridgemate when you run your Swiss program. In that case you could have best guess for the unfinished team results and use them for next round pairing.
Oct. 2, 2014
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