[xeno123]

I just played a robot MP tournament (48 players in three sections). My "Rank" ended up being shown as 1, but I in actuality ended up third overall (and also third in my section). So just wondering if this is a bug due to the new sectioning somehow? I was first in "Section C" but I assume that isn't used for anything yet.

Or was "Rank: 1" just a preliminary verdict and hence a tease?

[bd71]

xeno123, on 2013-June-24, 16:20, said:

I just played a robot MP tournament (48 players in three sections). My "Rank" ended up being shown as 1, but I in actuality ended up third overall (and also third in my section). So just wondering if this is a bug due to the new sectioning somehow? I was first in "Section C" but I assume that isn't used for anything yet.

Or was "Rank: 1" just a preliminary verdict and hence a tease?

My experience is that this number is likely accurate as of the time of display, but that it needs to be updated for a variety of reasons:

1. Other players may finish a board after you, changing your matchpoint/percentage score for that board and potentially changing your rank as well.

2. I don't believe that number is EVER updated on your screen for the results of your last board. So if you have a bad last board, you should expect to place lower-ranked than what was showing on your screen (or vice versa if you have a good board).

[ArtK78]

As I have seen it, Rank now indicates your present rank within your section.

I have no idea how Rank operates in lower flights in stratified games.

[barmar]

ArtK78, on 2013-June-24, 16:55, said:

As I have seen it, Rank now indicates your present rank within your section.

Correct. I also found it surprising at first, but Uday explained that it's because masterpoints are based on section rank, not overall.

[xeno123]

barmar, on 2013-June-25, 09:29, said:

Correct. I also found it surprising at first, but Uday explained that it's because masterpoints are based on section rank, not overall.

I still think there is something strange going on. If I look at my "Recent Tournaments" page, I'm seeing a number of recent "Rank 1" listings where I came second or third in my section. So maybe it has to do with ranking within your flight within your section? Not sure why that would be useful information.

Peter

[GreenMan]

I just now had a similar experience: showed Rank=1 for the last few boards, but I finished 3rd OA, 1st in B, 1st in C. The overall winner was 20 IMPs ahead of me, so I know it wasn't a last-board charge. It appears to me that that rank is where you stand in "your" stratum, not overall unless you're in stratum A.

This tournament had 21 tables, and I was -2 IMPs after the first two boards but ranked 4th; my overall ranking would have been 12th or so.

[barmar]

xeno123, on 2013-June-25, 20:43, said:

I still think there is something strange going on. If I look at my "Recent Tournaments" page, I'm seeing a number of recent "Rank 1" listings where I came second or third in my section. So maybe it has to do with ranking within your flight within your section? Not sure why that would be useful information.

I was talking about the rank that shows up WHILE you're playing in the tourney.

In Recent Tournaments, the rank that's shown is your rank in your stratum and section. So if you're 3rd in A and 1st in C (as you were in a recent tourney), it will say Rank = 1.

[Peter_f]

Is there an explanation of this A-B-C-section method anywhere?

Sorry, I don't understand this at all

[ArtK78]

Peter_f, on 2013-July-03, 01:45, said:

Is there an explanation of this A-B-C-section method anywhere?

Sorry, I don't understand this at all

A-B-C designate the strata in an ACBL BBO online pair game. If I remember correctly, the "C" stratum consists of 1/3 of the players in an event with the lowest masterpoint ranking, The "B" stratum consists of 2/3 of the players in the event with the lowest masterpoint ranking, and the "A" stratum is all of the players in the event. All players are ranked in Stratum A for masterpoint awards. The players in Strata B and C are eligible for ranking for masterpoint purposes for awards in Stratum B. And the players in Stratum C are eligible for ranking for masterpoint purposes for awards in Stratum C.

Players receive the highest award for which they are eligible. For example, if a pair in Stratum C earned .23 masterpoints for their finish in Stratum A, .36 masterpoints for its finish in Stratum B and .47 masterpoints for its finish in Stratum C, the pair would receive .47 masterpoints. If the pair's award for its finish in Stratum A or Stratum B were higher, the pair would receive the higher award ONLY. There is no downside to stratification, as it offers all pairs the same or additional awards as they would be entitled to if the event were not stratified.

The sections themselves are supposed to be divided to distribute the Strata A, B and C players equally between the sections. A pair game is divided into sections to increase the number of pairs getting section top awards and section second awards, etc. There is no other reason for a division of pairs into sections in an online game.

[barmar]

The explanation is online in the BBO Help system, on the page regarding ACBL Tournaments

http://www.bridgebas...ournaments.html

Quote

All ACBL pairs games on BBO are stratified into three Stratas, A, B and C. The Stratas are determined by the number of BBO and ACBL points held by players in each game. This means the Stratas are fluid and can change from game to game. The points held by the players in the given game are gathered and divided into the three Stratas, with Strata A being those players holding the most BBO and ACBL points, Strata B the next third highest and Strata C the players with the fewest points of the group.

The three groups of players in each Strata are now distributed among the sections as close to equal as we can manage and the game begins. This stratification allows us to award points to the players in each Strata for 1st, 2nd, 3rd, etc., and for Overall awards. Of course, a player placing in the overalls and in his section will be awarded the highest award for overall or section placement, not both.

We obviously haven't updated this to reflect that it also applies to robot tournaments, with the difference that no overall awards are currently awarded.

This is all very similar to the way stratification is done in f2f ACBL clubs and tournaments. Tournaments usually set the stratum thresholds beforehand, but clubs often adjust the boundaries after the game starts, to even out the sizes so that the most players have an opportunity for awards.

[Peter_f]

Thank you both very much for the explanation, Art & Barry

Peter

[NemoJames]

Does anyone actually understand all this? I just came 12th out of 12 and yet was ranked as coming 4th. Is this a way of making us feel we did better than we thought?
In the past I could see how I was doing by the ranking which updated as I went along but now I haven't a clue. Personally I am not interested in learning about stratification, stratum thresholds and section placement so I guess I will have to forget about the ranking.

[Bbradley62]

NemoJames, on 2013-August-24, 01:29, said:

Does anyone actually understand all this? I just came 12th out of 12 and yet was ranked as coming 4th. Is this a way of making us feel we did better than we thought?

It appears that your 12 players included 4 in the A stratus, 4 in the B stratus and 4 (including you) in the C stratus. You came in 12th among the 12 players, and 4th among the 4 C-stratus players. This isn't supposed to make you feel better, but it's supposed to provide the info that many lower-level players want: i.e., it answers the question "how did I do among my peers", as opposed to "how did I do against the experts".

[barmar]

Look at the column headings. You came in 12th in A, 8th in B, and 4th in C. That's how stratification works: you get ranked in your own stratum and all the higher strata as well.

When you come in at the bottom of the field, it doesn't make much difference. But if you scratch, you get masterpoints for the highest stratum that you placed in. Take a look at the player who won that tourney: he was also a C player, but he got masterpoints based on winning A. But the player who came in 4th was 2nd in C, and that may have paid more than 4th in A (in such a small tourney, maybe not, but in larger tourneys it often will).