Chess rating system

starting with win loss is better than starting with random numbers, IMHO. Both introduce error, but the error would seem to be greater with the random numbers.

I just wasn't clear exactly on how the two systems would be integrated. Any initial rating can't be based on win-loss record.

ichabod801 wrote:

Give the top guy 3000 and the bottom guy 0, and use linear interpolation based on rank for everyone else. That gives you an initial rating r_0. Then apply your method to get their base rating r_1. Here's the trick: if this system works at all, r_1 is a better estimation of a player's rating than r_0 is. So you could apply the system again using r_1 to calculate averages rather than r_0, and get an improved rating estimate r_2. Do you then use r_2 to calculate averages to get r_3?

OK to restate the above, one could use your rating system, or for that matter, the existing one, and then as a second step apply mine. (Although my step wouldn't make sense until a player had played a number of games.)  I think I'm on the same page with you now.

As far as the recursion aspect (r_3, etc.) I would say no.  Only applying an additional method completely independent of the other two would make sense.

imagine if for your first game you beat pelger on time. how cool would that be!

That would a nice feeling , I admit.

Hey does the rating start with 1200?

Wow, a lot of people are missing a lot of points here.

Your opponent's average rating and your average score against them (ergo # of wins, draws, losses) is just a statistical nicety. People improve, often by a large amount, over time, so their earlier results aren't reflective on their current level of play. The fact someone scored 50% against 1800s 2 years ago is meaningless if they are now scoring 50% against 2100s - but the 50% against 1800s will still be inbuilt into their win/loss/draw vs average opponent rating score.

As for 1200 being an arbitrary starting number - yes it is. But this is where the Glicko system comes into its own... you have a very high RD, which means your rating varies much more wildly in your first few games. This allows you to move *quickly* towards your 'correct' rating, and as you play more games the rating changes you get for results decrease, to reflect the increased stability of your rating.

A new 1200 player might get (say) 300 points for beating a 1500 player, but that same 1500 player WILL NOT LOSE 300 POINTS. The 1500 player will lose whatever he would normally lose to a 1200 player (40 points say). You might think this would create discrepancies in the average rating, but remember that if that same new 1200 player LOST to a 900 player, he would lose 300 points while the 900 player would gain 40 points. So it all nets up to about the same.

The rating system is definitely important for playing matches of about your level. For people near the middle of the range it doesn't matter so much, but if you are rated highly (2000+) you do not want to be constantly playing players who are much weaker than you. This is not some form of arrogance - simply a player wants a hard-fought, even battle against someone reasonably near his strength. Without ratings, a 2000+ rated player would have to play hundreds of 1200 players and beat them all very easily, and this would be no fun for either player.

One more point about playing people rated much lower than you to artificially raise your rating. This is a complete fallacy. You get better rating from playing stronger players than you. Yes, if you're 1600 it should normally be easy to beat a 1200 player, but the fact of the matter is that you have to beat the 1200 player 15 times for every loss. The risk/reward for playing players much lower than you is NOT beneficial to your rating. At the same time, it doesn't make you 'unrealistically' or 'artificially' strong if you get to 1500 by beating many 1200 players. If you manage to beat them so easily, clearly it indicates that you are so much better than them that you almost never lose.

It is a well known fact that in real-world FIDE ratings, 2700+ ratings are somewhat inflated by the fact that they only play amongst themselves and very very rarely against players less than 2650. You will find that where 2700+ players mix with under-2600 players in tournaments, the higher rated players' ratings often suffer, because it is actually very hard to achieve the expected high score against people considerably lower than you.

Not sure if it's been mentioned here, but to address the not-completely-arbitrary-in-my-view choice by chess.com of an entry rating of 1200, here's what the USCF does:

Age = (Tournament End Date - Birth Date)/365.25

Initial Rating = 50 x Age, from Age 3 through 26; = 1300 otherwise.

If a player does not provide a Birth Date, but is inferred to be an adult, then Initial Rating is set to 1300.

Given that accurate birth dates are not available on chess.com and that a significant portion of new players are probably (my guess) less than 26 years of age, it seems reasonable enough to choose the value of 1200 as an initial rating for all incoming players. Using Glicko, a player's rating will move reasonably fast to a decent approximation of playing strength.

I would not find it unreasonable - though a good implementation would probably be somewhat problematic - to use federation ratings as an alternate initial rating, if one could be confirmed. Given the resource requirements for such confirmation, this is certainly not worthwhile from a business point of view. And I'm sure that some individuals would list their starting rating at 2800 just to get the initial bump. Trusting the honor system when no vetting of credentials is possible would be bogus and foolhardy.

hi im new here..nice to see u guys

How accurate is the rating here in comparison 'real' rating? For example if I would would walk into a chessclub tomorrow and say I'm 1600 elo would that be pretty close to the truth? (I go between 1600-1700) It seems pretty accurate since we have more than 50,000 players at chess.com...

I play to try and get better and the rating system helps me measure my progress...I'm on the verge of losing to someone who is 400 points lower and for me it's a little kick up the arse...you have x many points come on boy you should know better...that's how it helps me anyway.

It's not a fixed score, it's an approximation that proves to be accurate if you could play 1000 games etc which you can't.  As far as I am aware it's an aid that's all.

well i dont really know :)

While one might dispute the value we personally attach to a rating system or the importance or lack thereof of one's individual rating to our well-being, the rating system serves other purposes, of course.

In Swiss-style tournaments, the presence of ratings permits a determination of a reasonable results outcome in a small number of games by pairing players by rating (i.e., 1 plays n/2+1, 2 plays n/2 + 2; then winners play winners, etc.). Additionally, it provides associations with a reasonable (again) method of determining strong players from among a very large population without having to schedule special events.

Obviously, there are other ways to accomplish either of these objectives, but ratings systems do the job nicely enough. Still, we all know that ratings systems are not infallible: a) closed pools of players can lead to bizarre results (e.g., Claude Bloodgood), b) ratings inflation, and c) individual obsession with ratings.

For many, a rating provides a form of motivation. For others, an annoying distraction. So, use 'em if you find value. Ignore 'em if you don't. It's nice to have that choice.

...this is what a lot of higher rated players do here..play only against those

with ratings that are about 400 pts lower than their own rating...meaning against

those they can surely beat...even if they get just 1 point for every game they win

after a thousand game they will be rated 2000...so before somebody puts you in

awe with their fantastic numbers check the averarage rating of their opponents

first...

I've already debunked this totally faulty reasoning.

I agree with marvellosity he has some solid insight to the questions at hand...nobody wants to play houndreds of easy matches of they are just going to be boring

I think points are gogus because they don't help you in any way all they do is tell you how good a person is so you can know if your good enough to play a person.But if you go to a place where they have chess so you can play so you can play someone else and someone asks you to play them they don't wear a thing around their necks saying 1381 points.

Um, spencer, go to a chess club and it's pretty obvious pretty quickly roughly how strong people are.

It is just what type of game is expected

If I don't get my average rating up soon, no-one will respect me!

On the other hand, I consistently beat players 1800+! So those that underestimate me due to my average opponent rating, well, they've got another thing coming!