Maybe saying 3/4 theoretical favorites won, with Park Yeonghun being the only exception.

Yeah, even underdog might be too strong. Whatever, don't take my question or potential revision as even a slight criticism. And thanks for the EGF ELO explanation.

I am not going to try to prove it, but I'd expect that 3/4 favorites winning was far more likely than 4/4 favorites winning, because there are four different ways that could happen, versus only one for all faves to win.

_________________
- Brady
Want to see videos of low-dan mistakes and what to learn from them? Brady's Blunders

Let's do some maths!

Taking the standard ELO win rates for rating difference from http://www.bobnewell.net/nucleus/bnewell.php?itemid=279 (Remi, is this applicable to WHR?)

Lee (3521) vs Tang (3429) 63%
Ke (3561) vs Rong (3231) 87%
Zhou (3444) vs Park (3425) 53%
Ahn (3348) vs Xie (3293) 58%

So chance of 4/4 is all of those multiplied together = 17%
Chance of 3/4 is complement of each one multiplied by the remaining others added together is = 10% + 3% + 15% + 12% = 30%
So if the prediction model is correct, the chance of it getting 3/4 is about twice that of getting 4/4.

Yes. The formula is P = 1.0 / (1.0 + 10.0 ^ (elo_difference / 400.0))

And do keep going. By using the complements you can use the same math to compute the probability of the outcomes 0/4 and 1/4 (which will both be small). And then by adding up the probabilities of the outcomes 4/4, 3/4, 1/4, and 0/4 and subtracting from unity get 2/4.

Surprised by how large that is? (compared to the others)

Do you think I don't know how to compute basic probabilities, Mike?

Glad that my intuition was right.

I do find this surprising though: If there was to be exactly one lower probability winner, there was a 50% chance it would be Park. Whodathunkit?

Uber, your last comment to Mike was a joke, right? Or do y'all have a history that I am unaware of? Or was his post secretly insulting in some way that I don't get?

_________________
- Brady
Want to see videos of low-dan mistakes and what to learn from them? Brady's Blunders

Semi final pairing(3 games match),

Lee Sedol vs Ahn Sungjoon
Park Younghoon vs Ke Jie

My last comment was a genuine question based on this (and other past posts) which seem rather patronising. But again I used a short word with not quite the right meaning so I changed it.

I didn't mean to seem insulting. There does seem to be common misunderstanding about expected results. So I was just trying to point out that if it had been taken all the way would have become clear to people that contrary to the expectations of most, those differences in rank were not enough to make the most likely single outcome other than "pure guess".

Missed opportunity, that's all.

For 3/4 there is a typo: 10% + 3% + 15% + 12% = 40% (not 30%).

Here's what I get for all the cases:
4/4 correct: 17%
3/4 correct: 40%
2/4 correct: 32%
1/4 correct: 10%
0/4 correct: 1%

Edit: Ok I ran a few more cases. Setting all 4 games to be 60/40 matchups, you'll mostly get 3/4 or 2/4 correct:
4/4 correct: 13%
3/4 correct: 35%
2/4 correct: 35%
1/4 correct: 15%
0/4 correct: 3%

Setting all 4 games to be 80/20 matchups, you'll mostly get 4/4 or 3/4 correct:
4/4 correct: 41%
3/4 correct: 41%
2/4 correct: 15%
1/4 correct: 3%
0/4 correct: 0.2%

Throw out stats when it is single game match. At this level of game, anything can happen.

Semifinals!

Ke Jie (#1, 3566) vs Park Yeonghun (#17, 3443):
That's right, Ke Jie is now ranked #1, the best go player in in the world, one single elo point above Park Jungwhan!
Park Yeonghun also moved up a few spots and is currently at his highest-ever rating, surpassing his previous peak way back in 2005.
Ke Jie should win 67% of the time according to WHR. They have played each other twice, in the 2013 Chinese A league. Ke Jie won both times.

Lee Sedol (#3, 3530) vs An Sungjoon (#40, 3356):
WHR predicts Lee Sedol to win 73% of the time. They have played 4 times so far, and the record stands 4-0 Lee Sedol.
An Sungjoon is 6p, I think he will be promoted if he wins this game, since he will be a finalist for an international title.

If these matches go as WHR predicts, Ke Jie and Lee Sedol will face each other for the first time in the MLily final, with WHR giving a scant 55% edge to Ke Jie.

As an aside, if you want to evaluate the accuracy of probabilistic predictions like these, check out Brier Score and friends.


Edit: Just noticed that the semifinals are best-of-3 matches. That means (according to the model) Ke Jie and Lee Sedol have 75% and 82% chance of advancing, respectively.

Given Lee's greater experience of multi-game finals* and ability to use the extra time well, I would give him a slight edge in the final. Ke Jie is a hot potato though.

* I think part of this experience will be the ability to learn from mistakes that cause a loss in an early game thus making each game not an independent event with the same probability of win.

So those win rates were enough to make the most likely single outcome 3/4 not the 2/4 of guesswork (thanks Ke Jie). That's not really so surprising after you already have 47% (thanks for spotting the mistake yoyoma) used up, though before I'd calculated those percentages I would have said 'pass' if you asked me whether 3/4 or 2/4 correct was more likely as I'm well aware binomial coefficients balloon in the middle, whereas for 4 80/20 matchups I would be pretty confident to say 2/4 would be unlikely by intuition, and yoyoma's calculations show that's the case, with 60/40 being the turning point at which 3/4 overtakes 2/4.

In the meantime, the ratings have changed a good bit:

Ke Jie - 3601 (+ 35)
Park Yeonghun - 3473 (+ 30)
Lee Sedol - 3490 (-40)
An Sungjoon - 3366 (+ 13)

The same players are the favorites, but Lee didn't do so well through October and November, while Ke Jie is still on fire.

WHR and/or the goratings database makes kibbitzing about ratings hard: the website now says that Ke Jie hit 3565 on 2014-08-03 and has been steadily rising since.

_________________
Occupy Babel!

Semi final - 11/22/15 1st game of 3;
Lee Sedol defeated Ahn Sungjoon by resign.
Ke Jie defeated Park Younghoon by resign.

2nd game - 11/24/15

FYI, Myungwan Kim will be doing live commentary of game #2 between Ke Jie and Park Younghoon tonight, starting at 7pm PST, you can watch live at http://youtube.com/c/USGOWeb/live or http://twitch.tv/usgoweb.

As a bonus, he'll review game #1 during the lunch break, between 8:30pm and 9:30pm PST.

See you there!

Semi final - 11/24/15 2nd game of 3;


Park Younghoon defeated Ke Jie by resign.
Park Younghoon vs Ke Jie - 1:1


Lee Sedol defeated Ahn Sungjoon by resign.
Lee Sedol vs Ahn Sungjoon - 2:0
Lee Sedol advances to Final!!!!!!!!!!!!


3rd game:11/25/15

Park's first game with Ke was interesting as the opening was similar to Ke's vs Lee Sedol recently, see viewtopic.php?p=195684#p195684. Did Myungwan Kim comment on this?