Just for fun, we’ve decided to give players in our Chess Eternament numerical ratings based on the English Chess Federation (ECF) system. Whenever you finish a game, you get a new rating based on your pre-game rating, your opponent’s pre-game rating, and the outcome of the game. (Results below.)
It works like this:
0. Everybody who hasn’t completed any games yet starts with 100 points. When you finish a game:
1. Take whichever is less: your opponent’s pre-game rating, or your pre-game rating plus 40.
1. Take your opponent’s rating. If it’s more than 40 points higher or lower than yours, round it “toward” your rating so that it’s exactly 40 points higher or lower.
2. If the game was a draw, the number from (1) is your new rating. Otherwise,
3. Add 50 points if you won, or subtract 50 points if you lost.
4. If your new rating is a negative number, set it to zero.
For those of you who like formulas, it works like this:
for Rold < Ropponent:
Rnew = min(Ropponent, Rold+40) – 50 + 100*n or
for Rold > Ropponent:
Rnew = max(Ropponent, Rold-40) – 50 + 100*n
(where n = 1 for a win, 1/2 for a draw, 0 for a loss).
Here are MuseBlog’s ratings (for standard chess only) as of April 17, 2010:
Piggy: 160 points
bookgirl_me, Jakob Wonkychair, peary_moppins, cromwell, Purple Panda: 150 points
Ducky: 140 points
Keiffer, and anyone who is just starting out and hasn’t finished a game yet: 100 points
SudoRandom: 90 points
mas0n, TMFA, RoseQuartz, Tesseract, Pseudonym: 50 points
Kiga: 10 points
Woah, this is cool. But what point value do you start on? Zero? If so, wouldn’t people who have won a single game have ninety points? (Forty points for step 1 plus fifty points for step 3?)
Everybody starts out with 100 points. I’ll add a “rule zero” to that effect.
Piggy: Something interesting happened in your game with SudoRandom. You went in with 150 points from your game with RoseQuartz. Sudo’s game with you was his first, so he had 100 points. Because your rating was more than 40 points higher than his,
you didn’t gain any points by beating himyou gained only 10 points by beating him, and he lost only 10 points by losing to you.The system is interesting, because weak players aren’t penalized much for losing to much stronger players, and strong players don’t gain
anythingmuch by beating much weaker ones.I’m assuming you mean my first finished game? I have another game going (in the loosest sense of the word) with Sequoia.
Yes, the first you completed. Unfinished games don’t change your rating.
Wait, why did Piggy’s rating not change? We both took my score plus forty, I think, making it 140, but then he gains fifty points from winning, right? So why doesn’t he have 190? Hm.
Oh, I see. He takes my pre-game rating, not my pre-game rating plus forty. This is a cool system!
I think it’s nicely designed. You can never lose points by beating someone with a lower rating
, but to gain points, you have to beat someone rated 40 points below you or higher. On the other side, when playing someone rated much higher than you, you gain a lot of points if you win, but you don’t lose many points if you lose. If you draw, you swap ratings (again, within the 40-point limit). Neat.Wait, you swap ratings? If I had had a draw with Piggy, my final score would have been 140, right?
Let’s see. You went in to the game with 100 points, vs. Piggy’s 150. So if you’d drawn the game, your new rating would be min(150, 140) = 140. His new rating would have been max(100, 110) = 110.
Sudo:
I checked the formula again, and it turns out he did gain a little. You were 50 points below him, so for the calculation we bump that up to 40 points, making 110. Then we add 50 points for the win, making 160. That’s only fair: a strong player ought to gain something for a win, even against a much lower-rated opponent.
I think I should be under the people who have 50 points.
Oh, wait, I didn’t see for standard chess only part.
3&c- I don’t understand. Shouldn’t Piggy have 200 and Sudo 50? Because it wasn’t a draw, right? The winner adds 50 points, and the loser subtracts 50. It looks like you’re using the system for a draw, but… I’m so confused.
Yes, I’m sorry. I left out one rule. Whenever the difference between the two players is more than 40, you round up or down from your own rating to make the difference 40. I’ll add it up top. That does change the result slightly.
Oh wait. I get it. Never mind.
The rating system is simpler than it sounds. Here’s another, equivalent way to calculate your new rating after a game:
If you win, take your opponent’s pre-game rating and add 50 points.
If you lose, take your opponent’s pre-game rating and subtract 50 points.
Exception: Your rating may not change by fewer than 10 or more than 90 points as the result of a single game.
If you draw, take your opponent’s pre-game rating.
Exception: Your rating may not rise or fall more than 40 points as the result of a single draw.
You always gain points when you win; you always lose points when you lose.
Okay… Somehow, I don’t get this all the way. Do these ratings only extend to normal chess? Otherwise, my total doesn’t really make sense unless POSOC started with less than 100…
Yes, they’re just for standard chess. One victory gives you 150 points.
Okay, that makes sense. Whoever wins this game (cromwell or myself) gets 200 points, right (and the other person is back at 100)?
We will see…It’s your turn, and it was when you posted.
That’s right. I’ll post the new numbers on the Chess Ladder.
I think I’d like to try a chess match. How do I sign up for one?
Just ask and the GAPAs will find you a partner.
(12) oxlin: How would you rank yourself? A (strong, win most games you play), B (medium strength), C (beginner, know how the pieces move but not much else)?
13- C. I’ve played once or twice before but pretty much all I remember is how the pieces move.
I’ll play. I’m pretty terrible myself.
Oh never mind you’re playing Gimanator. Who can I play?
Sudo: Enceladus, maybe?
Sure, if he’s up for another game!
Sure. I don’t have anything better to do.
Oh, and I want Black.
Alright.
SudoRandom and Enceladus: Messieurs, your board awaits.
But… It has me as white. Oh well, I don’t really care.