EMA vs Swiss/Buchholz system

News and discussion on tournaments been and gone.

Moderator: Shirluban

Post Reply
drob
Fresh Reacher
Fresh Reacher
Posts: 5
Joined: Sat Sep 19, 2009 7:06 pm

EMA vs Swiss/Buchholz system

Post by drob » Tue Dec 01, 2009 3:43 pm

Is a change possible now though? On an individual level, a system change like this would effect how player’s approach tournaments. On the level of the EMA, would they have to discard the EMA ranking system scores that have been collected up until now to start this new system?
Of course they don\'t need to change their ranking - ranking is based on how you place in tournaments; how you place in tournaments is irrelevant. You could, for all the EMA ranking care, just randomize who gets what spot and their ranking system would still work.

Obviously, changing how people place in tournaments will reflect in the rankings, but it\'d be such a slow change (due to how EMA uses a decaying results system) that there\'d be no harm in it. Indeed, you could even argue that it would be a good thing in that you see if people actually deserve the ranking they have or not.

In the end it doesn\'t matter though. My post was merely an exercise, nothing more.

User avatar
Shirluban
Moderator
Moderator
Posts: 780
Joined: Thu Jan 22, 2009 1:53 pm
Location: Svartalfheim
Contact:

Re:EMA vs Swiss/Buchholz system

Post by Shirluban » Tue Dec 01, 2009 7:35 pm

Tip to newcomers: read ==> this <== and ==> that <==.

One thing bother me in your table-point system, and it\'s not ties.

To take your example:
Imagine 2 tables, table A and B. On table A plays 1 good player (player A1), and three bad players. On table B plays 4 good players.
[...]
Now, after the game is finished, the tables will look like this, despite (or including) uma:
Player A1: A lot of points
Players A2-4: A lot of points minus
Player B1 (finished first on table B ): few points plus
Players B2-4: few points plus or minus
With the table-point point system, the low-skilled player A2 will get more points than the good players B3 and B4. Is it fair?

I don\'t say EMA system is fair either. But where EMA system favors a good players on a low-level table, a table-point system favors low-level players.
Cats don't do タンヤオ (tan-yao) but タニャーオ (ta-nya-o).
World Riichi Championship Rules 2022
Comparison of riichi rules around the world

gemma
Administrator
Administrator
Posts: 150
Joined: Sat Nov 03, 2007 12:45 am

Re:EMA vs Swiss/Buchholz system

Post by gemma » Tue Dec 01, 2009 10:04 pm

Hey drob, thanks for commenting! I hope you don\'t mind me writing about your blog post. I just really enjoyed it and thought it was a great contribution; it was a very interesting and well-thought out critique.

My comment on discarding the old rankings was because I wondered whether it would have too much of an effect on any new system adopted. In other activities I\'ve participated in, when a new system is adopted, the whole slate has been wiped clean to avoid any accusations or doubt etc.

You are right though, it is a decreasing ranking system so a new adoption could be gradual and/or they could increase the factor of depreciation on those results obtained under the old system.

However, as you said, it\'s all academic. I don\'t propose EMA change the way they work. But I do enjoy exploring all possibilities. ^.^

Mcgreag
Fresh Reacher
Fresh Reacher
Posts: 32
Joined: Sun Jul 05, 2009 10:56 am
Location: Sweden

Re:EMA vs Swiss/Buchholz system

Post by Mcgreag » Wed Dec 02, 2009 12:55 am

Shirluban wrote: With the table-point point system, the low-skilled player A2 will get more points than the good players B3 and B4. Is it fair?

I don\'t say EMA system is fair either. But where EMA system favors a good players on a low-level table, a table-point system favors low-level players.
The swiss system should normal take care of that. A weak player getting lots of points early will play stronger opposition in later rounds and not acquire any more points.

But when it comes to tiebreakers I am not sure sure Buchholz is the best. Buchholz can be highly dependent on luck in the draw, especially if there is no initial seeding. A good player might lose the tournament because he where drawn against very easy opponents instead of medium skilled ones (which he would still win against) in the first round.

Buchholz have been heavily used in Go tournaments as well as a tiebreaker (but under the name SoS, Sum of Opponents Score). But there more and more people starting to question the accuracy it provides.

drob
Fresh Reacher
Fresh Reacher
Posts: 5
Joined: Sat Sep 19, 2009 7:06 pm

Re:EMA vs Swiss/Buchholz system

Post by drob » Wed Dec 02, 2009 1:46 am

Shirluban wrote:Tip to newcomers: read ==> this <== and ==> that <==.

One thing bother me in your table-point system, and it\'s not ties.

To take your example:
Imagine 2 tables, table A and B. On table A plays 1 good player (player A1), and three bad players. On table B plays 4 good players.
[...]
Now, after the game is finished, the tables will look like this, despite (or including) uma:
Player A1: A lot of points
Players A2-4: A lot of points minus
Player B1 (finished first on table B ): few points plus
Players B2-4: few points plus or minus
With the table-point point system, the low-skilled player A2 will get more points than the good players B3 and B4. Is it fair?

I don\'t say EMA system is fair either. But where EMA system favors a good players on a low-level table, a table-point system favors low-level players.
While I\'m not interested in partaking in a discussion of this on RM, given that the obvious forum for it should be my own blog, I\'ll deign to answer this.

First of all, the example is stretched to absurdity as it is - Europe doesn\'t have many good mahjong players, and the chance of them ending up at the same table in a tournament is just so ridiculously low that I wouldn\'t know how to calculate it.

Okay, now that the snarkiness has been done with, let\'s get on with it. The example is based on extremes, and yes - in that scenario players B3 and B4 will be worse off than B2. However, keep in mind that we\'re still using scoring as a tie-breaker here - so player A2 will only have one good player (from the first table) that\'ll rack up scores for him, whereas players B3 and B4 will have 3 good players.

"My" system works across a lot of games, but breaks down in single-game examples. EMA\'s system doesn\'t work under either, really, but will be "more fair" in a single-game example. What I want to achieve is at the end of the day, the player who\'s played better than the rest - and yes, that includes tactical play - should be at the top of the list. EMA doesn\'t have that - what EMA has is a system where pure luck is a greater deciding factor than anything else. Hell, I placed 8/24 in Vienna, and I played that entire tournament drunk. There\'s something dodgy when that happens (and I attribute my placing so high on the first game of the day - I scored very well in it, and so kept my ranking quite high even if I ended up on a third and fourth place or something similar), don\'t you think? One game shouldn\'t be a deciding factor in a tournament.

@Mcgreag: good points all across - I\'m aware of how Go tournaments are held. Not sure what could be a better tie-breaker though. I think it\'s fair to say that it would work better in mahjong - you have 3 players (on each table) that you track; so any "bad luck" on seeding should sort itself out. I\'ll run the numbers from the tournament in Hannover some day and see what happens.

And now I leave, until Gemma decides to comment on another of my blag posts.

Robert
Junior Reacher
Junior Reacher
Posts: 88
Joined: Mon Feb 02, 2009 8:59 pm

Re:EMA vs Swiss/Buchholz system

Post by Robert » Wed Dec 02, 2009 2:16 am

Has anyone but me noticed that, when the uma is increased, the current system degenerates into something much like drob\'s system, but with a different tiebreaking mechanism?

User avatar
Shirluban
Moderator
Moderator
Posts: 780
Joined: Thu Jan 22, 2009 1:53 pm
Location: Svartalfheim
Contact:

Re:EMA vs Swiss/Buchholz system

Post by Shirluban » Wed Dec 02, 2009 7:36 pm

Robert wrote:Has anyone but me noticed that, when the uma is increased, the current system degenerates into something much like drob\'s system, but with a different tiebreaking mechanism?
It\'s what uma is designed for.

I talk about a real strong uma, like 30/10. Not the near-meaningless 9/3.

drob wrote:One game shouldn\'t be a deciding factor in a tournament.
I fully agree.
Unfortunately, with a table-point system the amound of points a player can earn is fixed. This mean, if a player loose only one session, he can\'t get back in top places. Unless every other good players fails too, for him the party is over.
Cats don't do タンヤオ (tan-yao) but タニャーオ (ta-nya-o).
World Riichi Championship Rules 2022
Comparison of riichi rules around the world

MortenA
Fresh Reacher
Fresh Reacher
Posts: 28
Joined: Mon Jan 19, 2009 7:14 pm
Location: Copenhagen, Denmark

Re:EMA vs Swiss/Buchholz system

Post by MortenA » Fri Dec 04, 2009 6:11 pm

Shirluban wrote:
Robert wrote:Has anyone but me noticed that, when the uma is increased, the current system degenerates into something much like drob\'s system, but with a different tiebreaking mechanism?
It\'s what uma is designed for.

I talk about a real strong uma, like 30/10. Not the near-meaningless 9/3.
Yes I would much rather see an increase in uma instead of tablepoints.
drob wrote:One game shouldn\'t be a deciding factor in a tournament.
I fully agree.
Unfortunately, with a table-point system the amound of points a player can earn is fixed. This mean, if a player loose only one session, he can\'t get back in top places. Unless every other good players fails too, for him the party is over.
Yes with a table-point system one is forced to gun for first place every time as a single 2nd place or at least at 3rd place might very well cost one first place in the tournament.
At least when the tournament is only 4 rounds long.

I quite like being able to play defensively and only go for second place if that\'s more beneficial to me.

Benjamin
Senior Reacher
Senior Reacher
Posts: 157
Joined: Sun Jan 18, 2009 1:49 am
Location: Tokyo, Japan

Re:EMA vs Swiss/Buchholz system

Post by Benjamin » Sat Dec 05, 2009 3:12 pm

I agree with Shirl and Morten. Incidentally, a higher uma was what I recommended from the beginning :P. 5/15 is enough to be significant, 3/9 isn\'t.

There\'s a reason for this. Adding a significant bonus to place encourages players to, in the last few rounds, play not to get the most points, but to get the highest place. This adds a significant layer of strategy, something many players who do not use uma don\'t know about. I\'ll leave it to other to provide examples, but needless to say they are many and they are a big part of what makes riichi mahjong interesting. Arguments to the contrary are like arguments that claim that dora is all about luck; they miss the point that you have control over how you play, how you use dora, how you aim your final hands.

If this bonus is less than a certain amount, the incentive is basically meaningless because, for the most part, aiming for a mangan hand will become the best strategy to get points. It really needs to be over a mangan, say 5-15 (10,000) to be significant.

Also, a table points system is a bad bad idea. I say this as someone who\'s benefited from it: I wish EMA would drop the table points system and instead convert 1 table point to 100 minipoints.

MortenA
Fresh Reacher
Fresh Reacher
Posts: 28
Joined: Mon Jan 19, 2009 7:14 pm
Location: Copenhagen, Denmark

Re:EMA vs Swiss/Buchholz system

Post by MortenA » Sat Dec 05, 2009 4:37 pm

Yeah an uma of 5/15 would be much better as I see it and I hope that the rules will be changed in that direction at some point.

And Ben we have to find something to disagree about soon or people will start thinking we are the same person :)

User avatar
Shirluban
Moderator
Moderator
Posts: 780
Joined: Thu Jan 22, 2009 1:53 pm
Location: Svartalfheim
Contact:

Re:EMA vs Swiss/Buchholz system

Post by Shirluban » Sat Dec 05, 2009 10:10 pm

MortenA wrote:And Ben we have to find something to disagree about soon or people will start thinking we are the same person :)
You mean some 3-headed freak?
(Count me in too :P )


Sorry for this off-topic comment.
Cats don't do タンヤオ (tan-yao) but タニャーオ (ta-nya-o).
World Riichi Championship Rules 2022
Comparison of riichi rules around the world

Benjamin
Senior Reacher
Senior Reacher
Posts: 157
Joined: Sun Jan 18, 2009 1:49 am
Location: Tokyo, Japan

Re:EMA vs Swiss/Buchholz system

Post by Benjamin » Mon Dec 07, 2009 4:12 pm

MortenA wrote: And Ben we have to find something to disagree about soon or people will start thinking we are the same person :)
30fu 4 han should be rounded up to 8000 and 2000/4000. It is just ridiculous to have to call "two thousand, thirty-nine hundred" in a game.

Post Reply