Why on earth did the rating go UP???

http://www.uschess.org/msa/XtblPlr.php?201512123342-006-15838355

Peter Barendt. rated 108 (p9)

r1: draws an unrated, post rating 103 (p3)

r2: loses to 104 (p9), post rating 126 (p13)

r3: loses to unrated, post rating 107 (p4).

So Peter lost 2 games, and his draw was to someone lower rated. But he still gains 3 points!  Does the uscf have some wacky formula for low rated players?

The rating change was minimal. It hardly seems like a fatal flaw in the rating system. Without doing the calculations, it makes some sense that since the absolute ratings floor is 100 in the USCF system, and he drew with somebody, he can't be the absolute worse player.

You can read all about the ratings system and how ratings are calculated.

http://glicko.net/ratings/rating.system.pdf

I disagree. If you draw someone rated 103-, and lose the rest of your games, that means your peformance was, at maximum, 103.  Therefore, someone rated 108 should at the very least not gain points.

Don't the current performances of all active players in the pool affect rating changes? If so, that may result in an adjustment of a few points.

Odd.

Even if all 4 players were rated the same, 1 draw and two losses should mean you lose rating points... at the very least not gain points.

Maybe it has something to do with how unrated players are treated?

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And really, the floor should not be so low. The day these kids learn all the rules and pay attention during th game they'll jump from 100 to 1000 in a few months and screw up all their opponent's rating along the way.

it will more than likely be something to do with the unrated he drew against. depending on how well the unrated did in the rest of the tourney/games to give a better idea of their strength. I think they try and make it fair that way

The unrated preformed worse than Peter's rating. The unrated ended up with a rating of 103. Peter's rating went from 108 to 111. So even the draw should have lost points it seems.

 You should go take a look at the USCF rating formulas. The fact that he played two unrated players has an impact.

Also, the rating changes are not just based on the ratings of the opponents but the expectancy of getting a certain score against those opponents. Add to that the way the first four games get rated, it makes it more complex.

In what way?

I know how the regular formula works already.

Even if it's some kind of estimated performance based on previous rounds, the unrated he drew lost all his other games.

The best result of the unrated he lost to was a draw against a 146 rated player in the previous round.

Correct. Drew a 1300 player once in the first round of an open. Expected score 100%. Won the game and lost 1 rating point.

I know this is old, but it shows how odd this is:

http://www.uschess.org/content/view/12211/726/

I enter rating of 108 and number of prior games as 9.

I had to enter opponents as rated 400, 400, 400, to make a total score of 0.5 net the player 3 rating points as happened in this tournament.

The actual ratings of the opponents were:

unrated -> 103
104 -> 126
unrated -> 107

For all three of these opponents, the only games that were won were against him.

 I'm not terribly invested in the result to go do the math myself, that is why I suggested looking at the formulas.

For unrated players, they get put through a first-pass formula to initalize a rating to be used in the overall calculations. What likely happened is that process gave his unrated opponents high enough initial ratings, that the player in question was able to increase in ratings based on what his expected results should have been.

Those initial ratings are then fed back through the formulas to give those unrateds their provisional ratings.

 That link you found is an estimator and often won't be 100% accurate.

Here, go have some fun.

http://glicko.net/ratings/rating.system.pdf

If he or she is provisional, it's very well possible to go up while losing.

Provisional ratings are figured based on taking the ratings of your first 25 opponents, adding 400 to those you beat, subtracting 400 from those you lose against (not to go below 100), and their rating for a draw.

Then, especially for provisional and unrated players, ratings are usually "re-rated".  "Unrated" is NOT lower than 108.  First they rate the event to get the unrated players' ratings.  Next, the "re-rate" the event based on the actual performance ratings of the unrated players.

So here's what may have happened: 

108 player loses to Unrated player in round 1.  Round 3 unrated opponent draws a 450.

108 player loses to a 104 the second round, round 1 unrated opponent beats a 693, Round 3 unrated opponent loses to a 550.

108 player loses to Unrated player in round 3.  Round 1 unrated opponent beats an 800

So in the first running of the ratings, Unrated Player 1 draws a 108, and beats a 693 and 800, which gives him (108 + 1093 + 1200)/3 = 800

Unrated player 2 is (450 + 150 + 508)/3 = 369

What matters is the end result, not game by game, so look at the final numbers.  Now, instead of a draw to an unrated, loss to a 104, and loss to an unrated, instead your rating is figured out based on a 108 drawing an 800 and losing to a 104 and 369.

If he is provisional, that loss to the 104 and 369 is factored as a 100.  So let's say the 108 was based on 7 games.  To figure out his new rating, you would take the following:

((108*7) + 800 + 100 + 100)/10 = 175 (which is up from 108).

So it is possible to gain.  You could also lose by winning a game when provisional.  If you have a provisional 2000 rating, and you beat a 1200, that's only 1600 factored in, your rating goes down.

Once you get past 25 games, at that point, you can't gain with a loss or drop with a win.

Look at section 2.6 in that document. Assume for a second his unrated opponents were both 8. They are assumed to have ratings of 400, (50 x age).

So, his oppenents are

• 400
• 400
• 104

and he scored 0.5. Again, without doing the math his expected score was probably less than that,  thus his rating increased.

Except that it did happen. (#10)

Odds are, that person had less than 25 games.  If you have less than 25 games, yes, it can easily happen!

Also, post 10 says he drew a 1300.  You can lose points on a draw, and expected score is never 100%.  A player rated 800 above someone else has an expected score of .991, meaning in a thousand games, he is expected to score 991 points, whether that be 9 losses, 18 draws, 6 losses and 6 draws, etc.

Had a look, but it gets tedious. No thanks :p

In nobodyreally's case, even if his oppenent had more than 25 games, if his expected score in the event was 5.0 and he got 4.5, his rating could go down.

I see it when the top players outrate most of their opponents and don't have the expected score.