NGS for Swiss Pairs
I run a Swiss Pairs event where pairs organise themselves a 12-board match against another pair on BBO (weekly), and the result of that game (match-pointed against a BBO-random field) is the result we run with.
Clearly every match in a given round will use (primarily) different boards. So to make it work in EBUSwissPairsScorer, I enter all boards wiwth a score of 0 and apply the match result as Adjustments to the VP total for the match. That all works fine and I can get next round assignments and a Bridgewebs display of results (on www.gcba.org.uk if you want to see it).
Question is: if and how these matches should be scored for NGS purposes.
Options: it seems that if the results are submitted for UMS with the travellers included (ie all flat boards) then UMS is calculated. If the travellers are edited out of the UMS file then the calculation is not done.
Uncertainty: is really about whether NGS processing will do something senisble enough with a set of flat travellers and a bundle of VP adjustments (in which case I include the travellers), or will it treat the results on the boards as what matters and process as if each match was a draw (in which case I edit out the travellers)?
Comments
I don't think that NGS would/should be completed on those matches...
The random BBO pairs that this is scored against cannot be added into the system to get a strength of field, to start of with.
I think you are in uncharted territory that wasn't contemplated when UMS and NGS were started.
Maybe best to contact Jonathan Lillycrop and give him details of number of matches so that the Club/County can be invoiced for the UMS. As Martin has said it is basically a head-to-head match, this was never considered possible in Pairs prior to Covid-19, and not for NGS calculation.
When we play a teams match (head-to-head) it does not count towards our sessions (on MyEBU) but the County does get charged for the UMS. UMS is due because a session does not need to be18 boards or more. However, I don't know about the system that does the calculation. I think that it would be better to avoid using the "upload" system unless given instructions.
The only downside is that some players might be missing the required "sessions" to qualify for the Bridge Magazine, but that may only be a very minor problem.
Interesting dilemma.
CMOT
The sessions are uploaded for UMS payment and magazine points on either option.
What you do have is SOpp (strength of opposition) which page 11 of the full NGS Guide suggests is based solely on whom you play against in a Swiss Pairs game.
"Things are different for a Swiss Pairs Movement. Here we take each match as a separate stanza within the event as a whole. For each match, we are playing against a single pair of opponents. Here, as in Bridge Club Live, it is by far best to take the grades of just your two opponents. The SOpp factor for one match is just the average current grade of your two opponents"
Yes I can see that it is possible to work out the Sopp. But the problem is supplying other results from the BBO random Field for each Swiss Pairs Match. In the BCL details, BCL had the results from the other tables (same hands) to work out where each pair came in the Field to see whether they did better than expected , or not so well.
I think submitting the travellers as you have them will cause problems as Many of the pairs did not get the equivalent of 50% on every board. I don't know what would happen sending up the figures with no travellers.
In effect you have 78 matches (13 matches by 6 rounds, all with a different set of boards ) to send up for the correct NGS. Even then I don't know if that will be an acceptable way to do it.
I hope I am wrong, interesting dilemma
CMOT
I don't think that applying NGS grading is appropriate in this case because of comparing results to different fields (in some respects, the type of event most closely resembles the elimination pairs event that is briefly covered in the masterpoints handbook as that event is the only one officially referred to where different fields are used for results comparisons).
Not inputting travellers is fine and should be sufficient to avoid NGS processing (since you'd only input VP scores and not %s presumably), but you can also add on code 12 which would make doubly sure. The appropriate charge and masterpoints should be calculated automatically by EBUScore.
"I don't think that applying NGS grading is appropriate in this case because of comparing results to different fields"
The comparing of results to different fields is irrelevant when our Strength of Opponents is determined by just the players at our own table.
The ability to arrange a match between two pairs playing a number of boards at a single table without movement while surrounded by a large number of other tables playing the same boards creating the ability to provide a meaningful duplicate score for the single table in which we are interested, is something that is so cumbersome at F2F bridge that it has almost never been done, but for online bridge it is so easy and makes various types of competition very possible. There is no reason why results obtained in this way should not be valid for NGS provided that there is a way of actually achieving it. All such events in Bridge Club Live count towards the BCL Grading Scheme upon which the NGS was largely based. BCL doesn't just have some Pairs League match events played in this way but for some years now BCL has run the World's only Double Elimination Knockout Pairs, and it is graded.
Barrie Partridge - CTD for Bridge Club Live
It sounds like it may be possible then... however, a couple of points...
Until lockdown I thought that the average standard in the BBOs ACOL room was quite low... I would aim to be about 1 IMP per board up at the end of 20 boards or so. If you bid and made a game, you would get about 2-3 IMPs as some would not bid game and others play badly and go off.
After lockdown the standard dropped considerably - so I aimed to be 3+ IMPs up. In fact, I gave up playing casually as the standard was so bad. If you bid and make a game, you end up with about +5 or 6 IMPs as so many end in the wrong contract or play so badly to go off.
The last time I played with my wife online, we ended 100 IMPs up after 20 boards!
It really feels like rubber bridge now, as if you have the majority of the points and get to have more games than the ops, you win. Over long matches, this would not be a big issue... over a short 12 board map, I think that this would be an issue - but what can you do?
Hi Patricks
Have looked at this and think my original comment still stands.
At NGS Procedural Guide For Scorers (in NGS <> help)
there is a comment
“3 WHAT DATA DOES THE SCORING SYSTEM HAVE TO INCLUDE?
For Swiss events, it is essential that the traveller line data for each board are included, as NGS needs to know what opponents each pair played against.”
My comment is that this is strange because that information (opponents) is the one thing that isn’t between and .
A Swiss Pairs XML file includes similar to the below
The Traveller Line is included after the
1
1
2
1
19
28
72
1
4H
E
10
-420
7
13
I am not sure how the information is processed but given the details from the Scorers Guide I think that to “upload” the information the upgrade the new NGS you need to supply the details for each “match” on each board between and .
I agree that BCL is the “Bees Knees” for a lot of competitions and I take my hat off to Phil and his team for getting a good system running. However, even BCL has everyone playing the same boards to make the comparison of the match points for each match on each board and ultimately amend the PPI for each player.
I assume that the program that reads the data needs all the data and makes sure that the answers for each part therein checks back(probably the match points). Therefore I recommend that before processing the travellers someone is contacted at EBU to confirm the situation. It may be possible to extract the XML file to notepad and clear some information and then convert back to XML to upload.
Hope this helps.
Very Interesting dilemma
CMOT
But surely the strengths of opponents aren't the players at our own table but the ones sitting in the same direction at all the other tables.
Example, you and partner (NS) average NGS 51, EW at your table average NGS 49, so to break even on the NGS you need to score 51% ? However the average NGS of all the other NS pairs could be 55 in which case they are effectively your opponents and you don't need to score 50% even to achieve par.
Oh Blast worked in word doh!
NGS Procedural Guide For Scorers
“3 WHAT DATA DOES THE SCORING SYSTEM HAVE TO INCLUDE?
For Swiss events, it is essential that the traveller line data for each board are included, as NGS needs to know what opponents each pair played against.”
My comment is that this is strange because that information is the one thing that isn’t between TRAVELLER_LINE and TRAVELLER_LINE
A Swiss Pairs XML file includes similar to the below
The Traveller Line is included after the
MATCH
ROUND_NUMBER 1 ROUND_NUMBER
NS_PAIR_NUMBER 1 NS_PAIR_NUMBER
EW_PAIR_NUMBER 2 /EW_PAIR_NUMBER
NS_VICTORY_POINTS 1 NS_VICTORY_POINTS
EW_VICTORY_POINTS 19 EW_VICTORY_POINTS
NS_SCORE 28 NS_SCORE
EW_SCORE 72 EW_SCORE
BOARD
BOARD_NUMBER 1 BOARD_NUMBER
TRAVELLER_LINE
CONTRACT 4H CONTRACT
PLAYED_BY E PLAYED_BY
TRICKS 10 TRICKS
SCORE -420 SCORE
NS_MATCH_POINTS 7 NS_MATCH_POINTS
EW_MATCH_POINTS 13 EW_MATCH_POINTS
TRAVELLER_LINE
I am not sure how the information is processed but given the details from the Scorers Guide I think that to “upload” the information the upgrade the new NGS you need to supply the details for each “match” on each board between Traveller_Line and Traveller_Line.
I agree that BCL is the “Bees Knees” for a lot of competitions and I take my hat off to Phil and his team for getting a good system running. However, even BCL has everyone playing the same boards to make the comparison of the match points for each match on each board.
I assume that the program that reads the data needs all the data and makes sure that the answers for each part therein checks back. Therefore I recommend that before processing the travellers somone is contacted at EBU to confirm the situation. It may be possible to extract the XML file to notepad and clear some information and then convert back to XML to upload.
Very Interesting dilemma
Ihave had to take out all the "<" and ">" to show on this comment board.
CMOT
This subject is covered in the Full Guide to the NGS in the section headed "Strength of Opponents and Strength of Field. It starts on Page 11. Quick link: https://www.ebu.co.uk/documents/miscellaneous/ngs/full-guide.pdf
Barrie Partridge - CTD for Bridge Club Live
To me that's the important paragraph, playing against a pair, your real opponents are the players sitting in your direction, NGS unknown !
For a 2-winner Mitchell, we need a subtle variation. Let’s say that you are
playing a full table full movement Mitchell without arrow-switch, and you and
all the other strong pairs are North South. You might think of taking a SOpp
factor from the East West pairs, but think again. Our real opponents are those
sharing the North South seats, as we are competing against them in the final
ranking list. If we used the East West pairs to calculate SOpp, then overall the
North South pairs will suffer a decline in grade, and the East West pairs will
enjoy a rise, which wouldn’t be fair
Indeed so for a Mitchell without arrow-switch, but it is important, too, to be aware that the way of calculating Strength of Opponents (SOpp) does depend on the format of the bridge that you are playing.
Barrie Partridge - CTD for Bridge Club Live
As Barrie say you must be conscious of the event type.
In a Swiss Pairs, the average of the NS pairs will be (roughly) equal to that of the EW pairs, because of the way in which matches are assigned. But SOpp does affect how you are expected to score, and that has to be the SOpp of the people against whom you play these boards.
So the documentation in the handbook that Swiss Pairs uses only the grade of the opposing pair does make sense. What remains unclear to me is whether the boards themselves are totally ignored in the NGS processing (ie just the VP score matters) in which case my dummy travellers do no harm. If the travellers are not ignored then either (a) the processing should run NGS when travellers are missing, or (b) these games cannot be NGS-processed.
NGS uses underlying matchpoint scores, not VP scores.
As Gordon says, and returning to the OP, Patrick, I cannot see any way that your games can be NGS-processed.
Barrie Partridge - CTD for Bridge Club Live
That's what I needed to hear; no problem, we just live without NGS