Chess.com doesn't use the Elo rating sysem.
New Elo System
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Tatzelwurm wrote:
Chess.com doesn't use the Elo rating sysem.
Yes it does, research online on what type of rating system chess uses.
May 10, 2015
0
#4
It uses the Glicko rating system. I got educated about this recently too.
https://en.wikipedia.org/wiki/Glicko_rating_system
TheronG12 wrote:
It uses the Glicko rating system. I got educated about this recently too.
Oh, well I guess I was wrong. Nevertheless, Chess.com should still change it's rating system.
Yeah, Chess.com's intial rating should be 2500! So that everyone would be masters!
May 11, 2015
0
#7
CHESS RATINGS -
HOW THEY WORK
Like it or not, we ALL have a chess rating. You may not care at all about your rating, or you may be whining every time it goes down in the slightest. You might be someone who plays a game a year, or someone who plays 1,000 a day. Still, there is a number out there that represents how well you play chess. Well, that's the theory, anyway.
To understand chess ratings you have to understand two things: #1 - that you have a TRUE rating that perfectly represents your strength of play, and #2 - that that TRUE rating will never be known and so we have to use statistics to get as close as possible to the truth. I'm writing this article in response to many people who ask about ratings and need a simple explanation of how they work. (I only know about all this because of a recent super-in-depth statistics course I took and my research in building Chess.com!)
There are two main rating systems, and each one has its merits.
The Elo System (used by the United States Chess Federation, FIDE, and many other online chess sites) is popular for two reason - it has been around for a long time, and it is simple. The idea is this: given two chess players of different strengths, we should be able to calculate the % chance that the better player will win the game. For example, Garry Kasparov has ~100% chance of beating my 4-year-old daughter. But he may only have a ~60% chance of beating another Grandmaster. So when playing that other Grandmaster, if he wins 6 games out of 10, his rating would stay the same. If he won 7 or more, it would go up, and 5 of less, his rating would go down. Basically, the wider the spread of the ratings, the higher percentage of games the higher rated player is expected to win. So to calculate a person's rating after playing a few games you calculate the average ratings of his opponents, and then how many games he was expected to win, and then plug it into a formula that spits out the new rating. Simple enough. Well, it turns out, that is maybe TOO simple.
The Glicko System (used by Chess.com, the Australian Chess Federation, and some other online sites) is a more modern approach that builds on some of the concepts above, but uses a more complicated formula. (This only makes sense now that we have computers that can calculate this stuff in the blink of an eye - when Elo created his system they were doing it on paper!) It is a bit trickier than the Elo system, so pay attention. With the Elo system you have to assume that everyone's rating is just as sure as everyone else's rating. So my rating is as accurate as your rating. But that is just not true. For example, if this is your first game on Chess.com and you start at 1200, how do we really know what your rating is? We don't. But if I have played 1,000 games on this site, you would be much more sure that my current rating is accurate. So the Glicko system gives everyone not only a rating, but an "RD", called a Rating Deviation. Basically what that number means is "I AM 95% SURE YOUR RATING IS BETWEEN X and Y." (Nerd Fact: In technical terms this is called a "confidence interval".) If this if your first game on Chess.com I might say, "I am 95% sure that your rating is somewhere between 400 and 2400". Well that is a REALLY big range! And that is represented by a really big RD, or Rating Deviation. If you have played 1,000 games and your rating is currently 1600 I might say "I am 95% sure your rating is between 1550 and 1650". So you would have a low RD. As you play more games, your RD gets lower. To add one extra wrinkle in there, the more recent your games, the lower your RD. Your RD gets bigger over time (because maybe you have gotten better or worse over time - I'm just less sure of what your actual rating is if I haven't seen you play recently). Now, how does this affect ratings? Well, if you have a big RD, then your rating can move up and down more drastically because your rating is less accurate. But if you have a small RD then your rating will move up and down more slowly because your rating is more accurate. The opposite is true for your opponent! If they have a HIGH RD, then your rating will change LESS when you win or lose because their rating is less accurate. But if they have a LOW RD, then your rating will move MORE because their rating is more accurate.
I wish there was some simple analogy to explain all this, but there isn't. It all comes back to this: you have a theoretically exact chess rating at any given moment, but we don't know what that is and so we have to use math to estimate what it is. There are really smart people out there who work on this stuff for a living, and at the end of it all we get to put their proven methods into our code so that we can all enjoy knowing what little numbers next to our name we deserve.
eg5309 wrote:
CHESS RATINGS -
HOW THEY WORK
Like it or not, we ALL have a chess rating. You may not care at all about your rating, or you may be whining every time it goes down in the slightest. You might be someone who plays a game a year, or someone who plays 1,000 a day. Still, there is a number out there that represents how well you play chess. Well, that's the theory, anyway.
To understand chess ratings you have to understand two things: #1 - that you have a TRUE rating that perfectly represents your strength of play, and #2 - that that TRUE rating will never be known and so we have to use statistics to get as close as possible to the truth. I'm writing this article in response to many people who ask about ratings and need a simple explanation of how they work. (I only know about all this because of a recent super-in-depth statistics course I took and my research in building Chess.com!)
There are two main rating systems, and each one has its merits.
The Elo System (used by the United States Chess Federation, FIDE, and many other online chess sites) is popular for two reason - it has been around for a long time, and it is simple. The idea is this: given two chess players of different strengths, we should be able to calculate the % chance that the better player will win the game. For example, Garry Kasparov has ~100% chance of beating my 4-year-old daughter. But he may only have a ~60% chance of beating another Grandmaster. So when playing that other Grandmaster, if he wins 6 games out of 10, his rating would stay the same. If he won 7 or more, it would go up, and 5 of less, his rating would go down. Basically, the wider the spread of the ratings, the higher percentage of games the higher rated player is expected to win. So to calculate a person's rating after playing a few games you calculate the average ratings of his opponents, and then how many games he was expected to win, and then plug it into a formula that spits out the new rating. Simple enough. Well, it turns out, that is maybe TOO simple.
The Glicko System (used by Chess.com, the Australian Chess Federation, and some other online sites) is a more modern approach that builds on some of the concepts above, but uses a more complicated formula. (This only makes sense now that we have computers that can calculate this stuff in the blink of an eye - when Elo created his system they were doing it on paper!) It is a bit trickier than the Elo system, so pay attention. With the Elo system you have to assume that everyone's rating is just as sure as everyone else's rating. So my rating is as accurate as your rating. But that is just not true. For example, if this is your first game on Chess.com and you start at 1200, how do we really know what your rating is? We don't. But if I have played 1,000 games on this site, you would be much more sure that my current rating is accurate. So the Glicko system gives everyone not only a rating, but an "RD", called a Rating Deviation. Basically what that number means is "I AM 95% SURE YOUR RATING IS BETWEEN X and Y." (Nerd Fact: In technical terms this is called a "confidence interval".) If this if your first game on Chess.com I might say, "I am 95% sure that your rating is somewhere between 400 and 2400". Well that is a REALLY big range! And that is represented by a really big RD, or Rating Deviation. If you have played 1,000 games and your rating is currently 1600 I might say "I am 95% sure your rating is between 1550 and 1650". So you would have a low RD. As you play more games, your RD gets lower. To add one extra wrinkle in there, the more recent your games, the lower your RD. Your RD gets bigger over time (because maybe you have gotten better or worse over time - I'm just less sure of what your actual rating is if I haven't seen you play recently). Now, how does this affect ratings? Well, if you have a big RD, then your rating can move up and down more drastically because your rating is less accurate. But if you have a small RD then your rating will move up and down more slowly because your rating is more accurate. The opposite is true for your opponent! If they have a HIGH RD, then your rating will change LESS when you win or lose because their rating is less accurate. But if they have a LOW RD, then your rating will move MORE because their rating is more accurate.
I wish there was some simple analogy to explain all this, but there isn't. It all comes back to this: you have a theoretically exact chess rating at any given moment, but we don't know what that is and so we have to use math to estimate what it is. There are really smart people out there who work on this stuff for a living, and at the end of it all we get to put their proven methods into our code so that we can all enjoy knowing what little numbers next to our name we deserve.
That's just a great post! Thanks.
eg5309 wrote:
CHESS RATINGS -
HOW THEY WORK
Like it or not, we ALL have a chess rating. You may not care at all about your rating, or you may be whining every time it goes down in the slightest. You might be someone who plays a game a year, or someone who plays 1,000 a day. Still, there is a number out there that represents how well you play chess. Well, that's the theory, anyway.
To understand chess ratings you have to understand two things: #1 - that you have a TRUE rating that perfectly represents your strength of play, and #2 - that that TRUE rating will never be known and so we have to use statistics to get as close as possible to the truth. I'm writing this article in response to many people who ask about ratings and need a simple explanation of how they work. (I only know about all this because of a recent super-in-depth statistics course I took and my research in building Chess.com!)
There are two main rating systems, and each one has its merits.
The Elo System (used by the United States Chess Federation, FIDE, and many other online chess sites) is popular for two reason - it has been around for a long time, and it is simple. The idea is this: given two chess players of different strengths, we should be able to calculate the % chance that the better player will win the game. For example, Garry Kasparov has ~100% chance of beating my 4-year-old daughter. But he may only have a ~60% chance of beating another Grandmaster. So when playing that other Grandmaster, if he wins 6 games out of 10, his rating would stay the same. If he won 7 or more, it would go up, and 5 of less, his rating would go down. Basically, the wider the spread of the ratings, the higher percentage of games the higher rated player is expected to win. So to calculate a person's rating after playing a few games you calculate the average ratings of his opponents, and then how many games he was expected to win, and then plug it into a formula that spits out the new rating. Simple enough. Well, it turns out, that is maybe TOO simple.
The Glicko System (used by Chess.com, the Australian Chess Federation, and some other online sites) is a more modern approach that builds on some of the concepts above, but uses a more complicated formula. (This only makes sense now that we have computers that can calculate this stuff in the blink of an eye - when Elo created his system they were doing it on paper!) It is a bit trickier than the Elo system, so pay attention. With the Elo system you have to assume that everyone's rating is just as sure as everyone else's rating. So my rating is as accurate as your rating. But that is just not true. For example, if this is your first game on Chess.com and you start at 1200, how do we really know what your rating is? We don't. But if I have played 1,000 games on this site, you would be much more sure that my current rating is accurate. So the Glicko system gives everyone not only a rating, but an "RD", called a Rating Deviation. Basically what that number means is "I AM 95% SURE YOUR RATING IS BETWEEN X and Y." (Nerd Fact: In technical terms this is called a "confidence interval".) If this if your first game on Chess.com I might say, "I am 95% sure that your rating is somewhere between 400 and 2400". Well that is a REALLY big range! And that is represented by a really big RD, or Rating Deviation. If you have played 1,000 games and your rating is currently 1600 I might say "I am 95% sure your rating is between 1550 and 1650". So you would have a low RD. As you play more games, your RD gets lower. To add one extra wrinkle in there, the more recent your games, the lower your RD. Your RD gets bigger over time (because maybe you have gotten better or worse over time - I'm just less sure of what your actual rating is if I haven't seen you play recently). Now, how does this affect ratings? Well, if you have a big RD, then your rating can move up and down more drastically because your rating is less accurate. But if you have a small RD then your rating will move up and down more slowly because your rating is more accurate. The opposite is true for your opponent! If they have a HIGH RD, then your rating will change LESS when you win or lose because their rating is less accurate. But if they have a LOW RD, then your rating will move MORE because their rating is more accurate.
I wish there was some simple analogy to explain all this, but there isn't. It all comes back to this: you have a theoretically exact chess rating at any given moment, but we don't know what that is and so we have to use math to estimate what it is. There are really smart people out there who work on this stuff for a living, and at the end of it all we get to put their proven methods into our code so that we can all enjoy knowing what little numbers next to our name we deserve.
The league system does all the positive feedback about the Glicko rating that you mentioned.
League System General Information:
- League Points
"Each ranked game you win earns you League Points while each lost one decreases your current LP. The exact amount of lost or earned League Points per game depends on your hidden Match Making Rating. If you have higher MMR than a set amount for your division you gain more LP per won game and lose less LP per lost game, if your MMR is lower you gain less and lose more LP per game".
- Tiers and Divisions
"Each tier (except Challenger and Master) contains five divisions, each division is numbered using roman numerals in a descending order from V(5) to I(1), with V being the lowest and I being the highest".
- Promotion and Demotion
Promotion
"When you reach 100LP you start your Promotion Series, where you have to win 2 out of your next 3 ranked games. If you win your Promotion Series you are promoted to the higher division and your LP is set to 0, if you lose your Promotion Series you remain in your current division, the LP lost is calculated normally.
If you reach 100LP in division I, you begin your Tier Promotion Series, where you have to win 3 out of your next 5 ranked games.
In very rare occasions, it's possible to be promoted twice after one Series, due to having a high MMR. For instance, someone in Gold V that duo queues often with his/her friend in Platinum III might have an unusually high MMR due to the players that he/she is matched against. As a result, his/her MMR may be 1 or 2 divisions higher than the average MMR of their current division. After winning their Promotion Series, there is a possibility that he/she may be promoted twice.
As of Season 4, it is possible, however rare, to skip promotional series. You will need to have an MMR one tier higher than your current placement. For example, if you are Gold V, so long as your MMR is Platinum IV or higher, you will instantly be promoted upon reaching 100LP. It is possible to skip divisions along side skipping promotional series".
Demotion
"Demotion happens when your current League Points reach 0 and you lose enough games to get demoted. When you are demoted you go to one division below your current and get 75 LP in that division e.g. if you are in Gold II and get demoted you will fall to Gold III and have 75LP.
There is also a demotion immunity grace period for several games, in which you can't get demoted to a lower division, which activates when you get promoted to a higher division. This is to make sure you don't fall to your previous division due to bad luck. However, one will demote out of Masters into Diamond I after playing at least 3 games, then losing with 0LP.
As of Season 4, it is possible to be demoted from a tier. If you are in division 5 of a tier and your MMR drops an entire tier, you will be warned about possible demotion. For example, a player in Gold V would receive a warning upon reaching Silver V MMR".
Challenger Tier
"The Challenger tier is the highest tier in the League ranked system and consists of the most skilled and competitive League of Legends players. Due to the competitive nature of this tier there is no LP inactivity decay but each time you gain the LP to move up one spot in the Challenger tier ladder someone gets pushed one spot down. After an inactivity period of 10 days, Challenger players are considered to be inactive and will be removed if another player qualifies to enter".
About 2-3 years ago League of Legends also used a similar rating system to the chess uses. They improved on their rating system in 2013.
"League system is a ranking system to find other players of a similar skill level to play with or against. In seasons one and two, the system used a single ladder with ranking determined by Elo rating system. In season three, the system uses six tiers with five divisions per tier, where ladder rankings within a league are determined by League Points (LP) and hidden Match Making Rating (MMR)".
The League of Legends staff decided to change their rating system for this reason.
"We decided to move to the new league system for a few reasons. For starters, having a single ladder with all ranked players doesn't provide a lot of incentive for advancement. When you’re ranked 290,000 and have 289,999 opponents left to pass on the way up, that process can seem meaningless and interminable. Tiers and divisions also provide milestones and manageable goals you can strive to achieve at your skill level. Through leagues we can move away from focusing on a single number as the core indicator of a player’s skill, and instead move toward something more compelling: competition on a small ladder with a relatable number of opponents".
May 12, 2015
0
#10
This league system is horrendously complicated. What do you do with players who don't want to participate (which would be the vast majority on this site)?
If you are so averse to rating numbers, simply call players 2200+ masters, 2000...2199 experts, 1800...1999 A class, &c. This is much simpler and has the advantage that every chess player will understand it.
May 12, 2015
0
#11
NewArdweaden wrote:
eg5309 wrote:
[big snip]
That's just a great post! Thanks.
No, it is not. Copying other people's content without attribution is just insolent. Eg5309 should have posted a link instead.
Tatzelwurm wrote:
NewArdweaden wrote:
eg5309 wrote:
[big snip]
That's just a great post! Thanks.
No, it is not. Copying other people's content without attribution is just insolent. Eg5309 should have posted a link instead.
It is a great post, no matter who wrote it.
The current elo system on Chess.com has many drawbacks. Most people are playing without a goal and are only wanting more elo. I suggest changing the elo system to a similar one that League of Legends have changed theirs into.
Read this post for information about this improved rating system.
http://forums.na.leagueoflegends.com/board/showthread.php?t=3004520
Read this wiki page for more information on the League of Legends rating system.
http://leagueoflegends.wikia.com/wiki/League_system