Junior Elo Ratings Article

"…One may safely assume that every tournament that a junior player plays helps to increase his playing strength. However, the overall level of the young players remains the same after a junior tournament because they all have the same K-factor. But this is an inadequate reflection of their real playing strength.

Players develop particularly rapidly between the age of 10 to 18 but in these years you now only gain Elo points from other players (unlike previously). Some of these rating points come from junior players who quit chess. However, because the playing strength of virtually all junior players increases from the age of 10 to the age of 18 years these junior players mainly gain rating points from adult opponents who “sponsor” the ratings of the juniors. As a result a lot of players ranging from 1000 to 2000 Elo points are underrated which also affected higher Elo levels.

In 2014 the K-factor for juniors was raised to 40. If a junior player (K=40) wins against an adult (K=20) the number of rating points the junior gains is twice as high as the number of rating points the adult loses. The junior player reaches the rating that expresses his playing strength adequately faster but the overall level of the Elo ratings also rises.

Today’s K=40 has the greatest impact when junior players play often against adults because they can show that their playing strength is not much ahead of their rating. But K=40 does not fully compensate the lowering impact the juniors have on the rating of the established players because the juniors gain rating points from players whose playing strength is adequately reflected in their Elo rating and who thus cannot fulfill their Elo expectation against underrated players. How junior players who lose Elo points and quit chess affect the ratings is still unclear.

Arpad Elo (1903-1992) already mentioned the deflationary impact of junior players on the Elo ratings. But if you look at the impact a single game has on the rating of an adult who loses against a junior you see that only a part of the rating loss of the adult is undeserved — depending on how much the junior player is underrated. To illustrate this phenomenon Berthold Plischke gave me the following example:

Junior J (Elo 1600) wins against adult A (also 1600). J wins 40*(1-0.5) = 20 points, A loses 20*(0-0.5) = -10. However, the 10 points A loses are not all undeserved losses: let’s say J had a playing strength of 1700. Then A should have lost 20*(0 - 0.36) = - 7.2. Therefore he only lost about 3 points undeservedly.

In the last two years the Indian Chess Federation had 30% more members! Presumably, most of the new members were juniors. Thus the Indian Chess Federation has a lot of junior players who have only few contacts to players from abroad. As a result the percentage of games in which a junior plays against another junior rises while the percentage of games in which a junior plays against an adult goes down. However, the level of the ratings can only change when players with a different K-factor play against each other. In view of the many Indian junior players the Elo level of Indian juniors will probably rise slower than in Germany.

Germany once also had a large increase of the number of junior players. From 1951-1991 the German Chess Federation increased the number of their members from 25,000 to 90,000. But back then the Elo rating was not introduced or the rating floor was too high for most juniors.

Let’s assume the following: if 100 players who are 30 years old and have an Elo average of 1800 only play against each other in the ten years to come what Elo level will these players have on average when they are 40? And then you take 100 10-year-olds with an Elo average of 1100 and for the next ten years they play only against each other — what an Elo level will they have when they are 20?

Proposals to calculate the Elo rating
Thanks to Berthold Plischke, responsible for controlling the “DWZ ratings” (the German ratings), and an expert in the field. When calculating the “DWZ”, junior players have certain privileges until they are 25 and thus are better integrated into the rating pool. At the age of 25 you should be close to the playing strength you can reach. In 2016, the German Chess Federation introduced another rule to fight the phenomenon of underrated players: if the tournament performance of a player is at least 300 points better than his current DWZ his tournament performance — and not his current DWZ rating — is taken to calculate the new DWZ rating of his opponents…"
en.chessbase.com/post/problems- … or-players

And your point is…??? That’s a description of FIDE ratings, not US Chess ratings.

When a young player, or any player for that matter, is rapidly improving, the U.S. Chess rating system already takes this into account, via bonus points, multiple passes, and other devices. There is no need to throw in a specific additional device just for age.

Bill Smythe

My point is that it’s an interesting article that I found worth sharing.

I wonder then why the Germans decided to adjust their system in the manner that they have. I seems to be a common circumstance across national and FIDE systems when it come to young players.

I think it’s interesting, in an “All Things Chess” sort of way. Probably not a USCF Issue though.

It may well be.

If you think it is a USCF issue, your answer to Tom’s question was disingenuous.

What caught my eye reading the article was the reference to the German rating system. It may or may not impact what US Chess is doing. I’m assuming that the Germans had the same tweaks available to them that US Chess has. If it does, it’s a US Chess issue. If not, it likely should be posted in a different forum.

Wow! That’s a spectacularly bad idea. Also, the assumptions are, frankly, silly.

Alex Relyea

Which? What Germany is doing, or that Brian is thinking that this is relevant to US Chess?

Neither. The assumptions in the article Mr. Lafferty quoted.

Alex Relyea

Perhaps someone like Mark Glickman, who has advised numerous organizations on ratings systems, might have detailed knowledge of the German ratings system. If someone has access to a document in English describing the German ratings system, please let me know, as I know very little German.

US Chess has two mechanisms designed to deal with improving players. One is the bonus system. I think a type of bonus system has been around since at least the 1980’s.

The second mechanism probably only dates back to the 2000/2001 revisions to the ratings formulas. We compute preliminary ratings for everyone (in what we call ‘step 4’.) Those ratings are then used as the ratings of your opponents when computing your new rating. This results in an ‘attenuation’ effect.

Suppose one of your opponents does much better than expected, going from 1600 to 1800 in step 4. Your game against him is then treated as if he was an 1800 player rather than a 1600 player, so a win would get you more points than it would otherwise and a loss would cost you fewer points than it would otherwise. Conversely, a player having a very bad performance has a lower step 4 rating, meaning a loss costs you more points and a win gets you fewer points.

I don’t think FIDE uses either of these types of adjustment mechanisms, but then FIDE’s rating system tends to assume that players make relatively slow gains in strength. (As did Arpad Elo in his original work, although he did allude to the necessity to make adjustments if assumptions about the pool of players change.)

Based on a series of conversations I had in Turin with Christian Krause, who I believe serves as a technical advisor to the German chess federation, their ratings system is much more like FIDE’s system than like the US Chess system and I believe they do not use either of these adjustment mechanisms.

Not relevant to this discussion, but I am sure I had learned about bonuses by 1971, when I had a 140-point rating gain from one tournament.

unless the system has again changed, then the 40K multiplier was not just for juniors. An adult with a rating under 1000 [and I remember an event where an adult had a 100 rating] would have the same 40 multiplier as a junior rated under 1000. I admit that the purpose of the sliding multiplier was to raise the ratings of under rated juniors faster than prior to that change. However, it applies to juniors and adults. Please don’t try to make a distinction that doesn’t truly exist.

Larry S. Cohen

That’s certainly possible, Bruce, the earliest copy of the ratings formula handout I have dates back to the mid 1980’s. In 1971 they were still computing ratings using ratings cards and desktop calculators. The first computerized ratings system was installed around 1977.

Bonuses were definitely part of the USCF rating system in the 1970’s—you doubled the rating gain above 40(?) regardless of the length of the tournament.

The whole initial post is very confusing (shock of shocks), and is a description of the FIDE system, not US Chess.

I’ve moved this topic from US Chess Issues to All Things Chess.

Makes me wonder how accurate computer ratings are.

Many chess programs, regardless if it’s a chess playing program, or a program with just a ton of problens to solve, try to estimate your playing strength. The almost have, so the user has some frame if reference for improving thier chess knowlege or playing skills or both.

But one has to wonder how close they get to an actual USCF or FIDE rating estimation.