[pran]

TimG, on 2015-October-12, 20:30, said:

Might it be the case that total MP is fine for events with short rounds but that VP is better for events with longer rounds?

Does anyone know of an online reference for Swiss Pair events? I've done some googling tonight, but can't find much of anything.

Most of the items I have found talk about pairing being staggered one round. Isn't this a thing of the past with the use of Bridge Mates?

To answer your last question:
Staggering one round allows the next round seating to be known immediately at the end of each round while not staggering imposes an extra delay between rounds, even with Bridgemates. This delay per round easily amounts to the time otherwise allowing another board per round.

[gordontd]

By the way, for anyone who was interested in the original topic of this thread, we did end up adding a regulation for mis-matches in Swiss Pairs scored by matchpoints - WB 3.5.3

[gordontd]

pran, on 2015-October-13, 01:44, said:

To answer your last question:
Staggering one round allows the next round seating to be known immediately at the end of each round while not staggering imposes an extra delay between rounds, even with Bridgemates. This delay per round easily amounts to the time otherwise allowing another board per round.

My experience is that the additional time is much less than this. However, when the rounds are short and there are a lot of them, the downsides of round-in-arrears are reduced.

[pran]

gordontd, on 2015-October-13, 01:47, said:

My experience is that the additional time is much less than this. However, when the rounds are short and there are a lot of them, the downsides of round-in-arrears are reduced.

I figure 7 minutes per board. Instead of moving directly to their next tables all players must wait for the information on their new seatings to be distributed and understood before they can move. How long does that take according to your experience?

(My experience is that players who have completed a round early often leave the table for various reasons, do you have some kind of regulation requiring all players to remain patiently at their tables until they are told where to go next?)

[gordontd]

pran, on 2015-October-13, 02:03, said:

I figure 7 minutes per board. Instead of moving directly to their next tables all players must wait for the information on their new seatings to be distributed and understood before they can move. How long does that take according to your experience?

(My experience is that players who have completed a round early often leave the table for various reasons, do you have some kind of regulation requiring all players to remain patiently at their tables until they are told where to go next?)

Your formulation is that a three-board round would take 28 minutes with current-round assignments, whereas I would expect it to be about 25 minutes.

We often have a monitor displaying the assignments for those who have left their tables before the end of the round.

[pran]

gordontd, on 2015-October-13, 03:55, said:

Your formulation is that a three-board round would take 28 minutes with current-round assignments, whereas I would expect it to be about 25 minutes.

We often have a monitor displaying the assignments for those who have left their tables before the end of the round.

With medium experienced players we allocate 7 minutes/board plus 2 minutes for the round shift, or 23 minutes/round with 3 boards.

Our scoring program offers a facility to perform the draws for next round once 95% of the scores in the current round have been entered, thus avoiding the staggering. To my knowledge this facility is little used (if any at all) here and our players apparently have no problem with the way we do things.

Our experience and simulation has confirmed that staggering has little impact provided the number of rounds is at least 8.

[TimG]

gordontd, on 2015-October-13, 01:37, said:

Did you find the basic articles on David Stevenson's website?

Yes, I did find two articles on David's website. They were helpful to get a basic understanding, but I am now looking for something more.

A few questions:

1) I am in the US where players are used to playing 2 or 3 boards per round (24-28 in a session) in club play, often in a Mitchell movement. I think that players (especially at the club level) enjoy the social aspect of frequently switching opponents. I think they would resist a change to Swiss Pairs if they played against only 4 opponents in a session. So, I am particularly interested in how efficiently Swiss Pairs can be run if there are something like 8 rounds of 3 boards each. Does the pairing time add significant time to the event?

2) For multiple session events, let's just focus on two sessions for simplicity, is there typically a qualifying session and a finals/consolation session?

3) I imagine that including a match element to the scoring helps to retain interest late in an event even for those that are apparently out of the running. But, there must still be some inclination to drop from an event if a pair is doing poorly. Does this something that is acceptable? I can remember times many years ago where it was routine for Swiss Team participants to drop from an event with a couple matches yet to be played. I have not seen this recently, but I wonder if this might be the case when there is not a "complete movement" that must be finished.

4) Is there "stratification" in Swiss Pairs? It is the way of the game in the US today.

I understand I'm hijacking a thread, I hope no one minds.

[RMB1]

TimG, on 2015-October-13, 06:43, said:

A few questions:

• With our hardware/software, generating and displaying the assignments/pairings is not a factor. But current-round assigning does not allow for tables to finish late and the pairs catch up in the next round. Round-in-arrears for 3-board rounds copes better with slow tables.
  
• We usually play through, but there are lots of possibilities for splitting into sections for later sessions.
  
• Giving up mid-session is "frowned upon" - there can be post-event disciplinary sanctions. We allow pairs to withdraw between sessions and do have stand-by pairs at the start of a session who can make-up a half table.
  
• We do stratify master-point awards and prizes for overall ranking. For long rounds (6,7,8 boards) we award master-points per "match" won: these are not stratified.

Quote

I understand I'm hijacking a thread, I hope no one minds.

GordonTD has an answer to the OQ (original question)

[TimG]

RMB1, on 2015-October-13, 07:25, said:

• We do stratify master-point awards and prizes for overall ranking. For long rounds (6,7,8 boards) we award master-points per "match" won: these are not stratified

No masterpoints for shorter matches? Seems reasonable, but also awarding masterpoints for shorter matches (meaning more people win masterpoints) also seems like a possible draw.

[WellSpyder]

TimG, on 2015-October-13, 06:43, said:

I am in the US where players are used to playing 2 or 3 boards per round (24-28 in a session) in club play, often in a Mitchell movement. I think that players (especially at the club level) enjoy the social aspect of frequently switching opponents. I think they would resist a change to Swiss Pairs if they played against only 4 opponents in a session.

I agree people are likely to resist change. My perspective, though, when we play Swiss Pairs once a month at the club, is that in many ways it feels more sociable playing 8 boards against the same opponents, giving time for more interaction and a decent contest, rather than just a random brief interlude in an overall evening of chopping and changing.

[pran]

TimG, on 2015-October-13, 06:43, said:

Yes, I did find two articles on David's website. They were helpful to get a basic understanding, but I am now looking for something more.

A few questions:

1) I am in the US where players are used to playing 2 or 3 boards per round (24-28 in a session) in club play, often in a Mitchell movement. I think that players (especially at the club level) enjoy the social aspect of frequently switching opponents. I think they would resist a change to Swiss Pairs if they played against only 4 opponents in a session. So, I am particularly interested in how efficiently Swiss Pairs can be run if there are something like 8 rounds of 3 boards each. Does the pairing time add significant time to the event?

2) For multiple session events, let's just focus on two sessions for simplicity, is there typically a qualifying session and a finals/consolation session?

3) I imagine that including a match element to the scoring helps to retain interest late in an event even for those that are apparently out of the running. But, there must still be some inclination to drop from an event if a pair is doing poorly. Does this something that is acceptable? I can remember times many years ago where it was routine for Swiss Team participants to drop from an event with a couple matches yet to be played. I have not seen this recently, but I wonder if this might be the case when there is not a "complete movement" that must be finished.

4) Is there "stratification" in Swiss Pairs? It is the way of the game in the US today.

I understand I'm hijacking a thread, I hope no one minds.

I can answer this based on Scandinavian experience (assuming "modern times" with computer scoring and pairing):

1:
No, there will be no delay if the pairing in round 3 is based upon the stanza after round 1, round 4 based on round 2, and so on.

No, there will probably not be any significant delay if this pairing is done for each round based upon the stanza after 95% of the boards in the last previous round (e.g. round 1 for round 2, round 2 for round 3 and so on) have been completed.

Yes, some significant delay must be expected if the pairing is done after the last previous round has been completed.

2: Do as you like, we most often have two or more sessions effectively contiguous as one complete event.

3: I am not aware of this ever having been a problem with us.

4: I am unsure of what is meant by "stratification", but if it implies some compensation when a currently very high ranked pair is drawn against a currently very low ranked pair then this is not at all an issue here.

The following points might be relevant in this connection:

a: there is no masterpoints or similar for any individual round although an organizer sometimes offer gifts to round winners.

b: seatings are always based on the accumulated (total) stanza at the time, not just on the results in the last completed round alone.

c: Our scoring program appears very competent in optimal seating across the entire field.

[TimG]

Does ACBLScore support Swiss Pairs?

What software do you use with the BridgeMates? This software has the option of staggering the pairings or waiting until all boards are complete? Or, do you manually indicate when to start pairings?

Are there minimum field sizes that make Swiss Pairs feasible? Or, small sizes that make a regular MP event a better option?

[pran]

TimG, on 2015-October-13, 08:17, said:

Does ACBLScore support Swiss Pairs?

What software do you use with the BridgeMates? This software has the option of staggering the pairings or waiting until all boards are complete? Or, do you manually indicate when to start pairings?

Are there minimum field sizes that make Swiss Pairs feasible? Or, small sizes that make a regular MP event a better option?

I have no idea about ACBLScore.
We use Ruter (a Swedish program).

Ruter allows us to draw (automatically) when last round is 95% completed, when last round is completed, or when previous round is completed. (We may even cancel an automatic draw and force a new draw manually at any time.)

Number of rounds should be at least 8, exceed the number of prizes and preferably be between 20% and 40% of the number of contestants.

[gordontd]

TimG, on 2015-October-13, 08:17, said:

Does ACBLScore support Swiss Pairs?

What software do you use with the BridgeMates? This software has the option of staggering the pairings or waiting until all boards are complete? Or, do you manually indicate when to start pairings?

Are there minimum field sizes that make Swiss Pairs feasible? Or, small sizes that make a regular MP event a better option?

In the EBU we have used Jeff Smith's SwissPairsScorer for a number of years and are now taking it over as the rebranded EBUscore which is free to EBU affiliated clubs.

We have the option at the start of specifying current-round assignments or round-in-arrears, but we manually select the moment at which to do the assignments so we can do it before everyone is finished if we want.

[TimG]

pran, on 2015-October-13, 09:34, said:

Ruter allows us to draw (automatically) when last round is 95% completed, when last round is completed, or when previous round is completed. (We may even cancel an automatic draw and force a new draw manually at any time.)

Number of rounds should be at least 8, exceed the number of prizes and preferably be between 20% and 40% of the number of contestants.

When you do 95% pairing, am I correct in assuming that the 95% of boards that have been played are scored for pairing purposes?

At least 8 rounds? So, an evening of four seven-board rounds would not be desirable no matter the size of the field?

[gordontd]

I've run single-session Swiss Pairs in clubs and used 5x5-board rounds, which is a reasonable balance. It still takes longer than a normal 24/26 board game though.

[pran]

TimG, on 2015-October-13, 12:05, said:

When you do 95% pairing, am I correct in assuming that the 95% of boards that have been played are scored for pairing purposes?

I do not know the algorithm in detail but observe that pairing is always done based on the total score percentage for each contestant involved at the time of the pairing. Thus different contestants might have their percentages based on different number of boards when 95% scoring is used.

And again please be aware that I have no experience with 95% scoring, most of us here (including me) just don't like it.

TimG, on 2015-October-13, 12:05, said:

At least 8 rounds? So, an evening of four seven-board rounds would not be desirable no matter the size of the field?

Correct. We do instead run 9 three-board rounds.