Board Game Arena

Today the ELO scoring has felt off for me. I don't know if it's just me. I gained 11 points winning against a player around the same score as me. Then I also gained 11 points by winning against a player with 120+ more ELO than me. And when losing against similarly skilled players, I'm losing around 30 points. This doesn't feel right at all.

MidwayMonk wrote: ↑04 August 2023, 02:04 Today the ELO scoring has felt off for me. I don't know if it's just me. I gained 11 points winning against a player around the same score as me. Then I also gained 11 points by winning against a player with 120+ more ELO than me. And when losing against similarly skilled players, I'm losing around 30 points. This doesn't feel right at all.

Feelings have nothing to do with it. There is a formula that strictly determines ELO changes. Have you read the FAQ "How is my ELO ranking computed?" Your K factor may differ for each game you play until you've played each one at least 20 times. When your K factor is 60 you will have wild swings.

I'm not new to BGA. I made this account because I switched computers and I completely forgot what my old account was. I know it's not about feelings. It's a figure of speech. I know it's an algorithm. But never before have I received 11 points for both beating a player at my same score, and beating a player with 120+ score more than me, as well as losing 33 points for losing to a player with a close score to mine.

I ask if it's felt strange to anyone else because I'm also having issues with the site itself, needing to constantly refresh the page since yesterday as well.

Are these comparisons in the same game? If not, you have probably different K factors. You could provide the table numbers so others can check.

MidwayMonk wrote: ↑04 August 2023, 14:59 But never before have I received 11 points for both beating a player at my same score, and beating a player with 120+ score more than me,

Can you link to the game where you beat the 120+ player? You should definitely get more Elo when you beat someone with 120 Elo points above you. At least if it is a one vs. one game. For larger player counts, it can be different.

And, as the others pointed out, you can't compare between different games, when you start with a new account, you will have different K factors for different games.

MidwayMonk wrote: ↑04 August 2023, 02:04 Today the ELO scoring has felt off for me. I don't know if it's just me. I gained 11 points winning against a player around the same score as me. Then I also gained 11 points by winning against a player with 120+ more ELO than me. And when losing against similarly skilled players, I'm losing around 30 points. This doesn't feel right at all.

I quickly scanned all of your games from the past half day or so, and nothing looked odd to me based on what I know about ELO calculations.

dschingis27 wrote: ↑04 August 2023, 18:02Can you link to the game where you beat the 120+ player? You should definitely get more Elo when you beat someone with 120 Elo points above you. At least if it is a one vs. one game. For larger player counts, it can be different.

This. With a link to the game in which this happened, it can easily be verified what the K factor was and whether the calculation was correct.

Yes! And I finally have a good example.

I just finished a game of Pandemic - 404694066. My ELO ranking is over 1200 but the other three players are in the 100s. It is a cooperative game; normally everyone earns the same ELO for winning, and that is based off our average ELO. However, one player earned 48 ELO, I earned 10, and the other two earned 9. If anything, I should earn less ELO than other players - definitely not more.

dizzymisslizzy17 wrote: ↑07 August 2023, 01:35 Yes! And I finally have a good example.

I just finished a game of Pandemic - 404694066. My ELO ranking is over 1200 but the other three players are in the 100s. It is a cooperative game; normally everyone earns the same ELO for winning, and that is based off our average ELO. However, one player earned 48 ELO, I earned 10, and the other two earned 9. If anything, I should earn less ELO than other players - definitely not more.

When you mouseover the ELO scores it says "Details are not yet available for a cooperative game'" That's where you'd normally see the K factor and probability of a win, etc., for a competitive game. Without seeing the precise inputs you can't explain what happened. I don't know if details will ever be available because ELO was not even designed for multi-player competitive games, let alone cooperative games. It is frankly silly to even apply it to cooperative games, but because players believe life has no meaning on BGA without ELO they did something to try to implement it.

"Changing ELO points for cooperative games" is a thread with some comments and links from a BGA developer (ufm) about problematic issues with ELO in cooperative games.

dizzymisslizzy17 wrote: ↑07 August 2023, 01:35 Yes! And I finally have a good example.

I just finished a game of Pandemic - 404694066. My ELO ranking is over 1200 but the other three players are in the 100s. It is a cooperative game; normally everyone earns the same ELO for winning, and that is based off our average ELO. However, one player earned 48 ELO, I earned 10, and the other two earned 9. If anything, I should earn less ELO than other players - definitely not more.

The +28 ELO player hadn't played many games so far, so they have a higher K factor which explains their extra points.

The 9 vs. 10 is likely just a (presentation) rounding issue. If I remember correctly, ELO is actually calculated to more decimal points, but they only show integers.