diff --git a/server/ladders-local.ts b/server/ladders-local.ts
index 14ee0774b4ebe..6679b77a31409 100644
--- a/server/ladders-local.ts
+++ b/server/ladders-local.ts
@@ -171,30 +171,7 @@ export class LadderStore {
updateRow(row: LadderRow, score: number, foeElo: number) {
let elo = row[1];
- // The K factor determines how much your Elo changes when you win or
- // lose games. Larger K means more change.
- // In the "original" Elo, K is constant, but it's common for K to
- // get smaller as your rating goes up
- let K = 50;
-
- // dynamic K-scaling (optional)
- if (elo < 1200) {
- if (score < 0.5) {
- K = 10 + (elo - 1000) * 40 / 200;
- } else if (score > 0.5) {
- K = 90 - (elo - 1000) * 40 / 200;
- }
- } else if (elo > 1350 && elo <= 1600) {
- K = 40;
- } else {
- K = 32;
- }
-
- // main Elo formula
- const E = 1 / (1 + Math.pow(10, (foeElo - elo) / 400));
- elo += K * (score - E);
-
- if (elo < 1000) elo = 1000;
+ elo = this.calculateElo(elo, score, foeElo);
row[1] = elo;
if (score > 0.6) {
@@ -321,6 +298,37 @@ export class LadderStore {
return `${output}| ${ratings[3]} | ${ratings[4]} | ${ratings[3] + ratings[4]} | `;
}
+ /**
+ * Calculates Elo based on a match result
+ */
+ calculateElo(oldElo: number, score: number, foeElo: number): number {
+ // The K factor determines how much your Elo changes when you win or
+ // lose games. Larger K means more change.
+ // In the "original" Elo, K is constant, but it's common for K to
+ // get smaller as your rating goes up
+ let K = 50;
+
+ // dynamic K-scaling (optional)
+ if (oldElo < 1200) {
+ if (score < 0.5) {
+ K = 10 + (oldElo - 1000) * 40 / 200;
+ } else if (score > 0.5) {
+ K = 90 - (oldElo - 1000) * 40 / 200;
+ }
+ } else if (oldElo > 1350 && oldElo <= 1600) {
+ K = 40;
+ } else {
+ K = 32;
+ }
+
+ // main Elo formula
+ const E = 1 / (1 + Math.pow(10, (foeElo - oldElo) / 400));
+
+ const newElo = oldElo + K * (score - E);
+
+ return Math.max(newElo, 1000);
+ }
+
/**
* Returns a Promise for an array of strings of s for ladder ratings of the user
*/
diff --git a/server/ladders-remote.ts b/server/ladders-remote.ts
index 95a6721229dad..5fbbc8d749453 100644
--- a/server/ladders-remote.ts
+++ b/server/ladders-remote.ts
@@ -61,7 +61,9 @@ export class LadderStore {
* Update the Elo rating for two players after a battle, and display
* the results in the passed room.
*/
- async updateRating(p1name: string, p2name: string, p1score: number, room: AnyObject) {
+ async updateRating(p1name: string, p2name: string, p1score: number, room: AnyObject): Promise<[
+ number, AnyObject | undefined | null, AnyObject | undefined | null,
+ ]> {
if (Ladders.disabled) {
room.addRaw(`Ratings not updated. The ladders are currently disabled.`).update();
return [p1score, null, null];
@@ -101,18 +103,16 @@ export class LadderStore {
if (p2) p2.mmrCache[formatid] = +p2NewElo;
room.update();
+
const [data, error] = await ladderUpdatePromise;
- let problem = false;
+ let problem = false;
if (error) {
- if (error.message === 'stream interrupt') {
- room.add(`||Ladder updated, but score could not be retrieved.`);
- } else {
- room.add(`||Ladder (probably) updated, but score could not be retrieved (${error.message}).`);
+ if (error.message !== 'stream interrupt') {
+ room.add(`||Ladder isn't responding, score probably updated but might not have (${error.message}).`);
+ problem = true;
}
- problem = true;
} else if (!room.battle) {
- Monitor.warn(`room expired before ladder update was received`);
problem = true;
} else if (!data) {
room.add(`|error|Unexpected response ${data} from ladder server.`);
@@ -132,37 +132,7 @@ export class LadderStore {
return [p1score, null, null];
}
- let p1rating;
- let p2rating;
- try {
- p1rating = data!.p1rating;
- p2rating = data!.p2rating;
-
- let oldelo = Math.round(p1rating.oldelo);
- let elo = Math.round(p1rating.elo);
- let act = (p1score > 0.9 ? `winning` : (p1score < 0.1 ? `losing` : `tying`));
- let reasons = `${elo - oldelo} for ${act}`;
- if (!reasons.startsWith('-')) reasons = '+' + reasons;
- room.addRaw(Utils.html`${p1name}'s rating: ${oldelo} → ${elo}
(${reasons})`);
- let minElo = elo;
-
- oldelo = Math.round(p2rating.oldelo);
- elo = Math.round(p2rating.elo);
- act = (p1score > 0.9 || p1score < 0 ? `losing` : (p1score < 0.1 ? `winning` : `tying`));
- reasons = `${elo - oldelo} for ${act}`;
- if (!reasons.startsWith('-')) reasons = '+' + reasons;
- room.addRaw(Utils.html`${p2name}'s rating: ${oldelo} → ${elo}
(${reasons})`);
- if (elo < minElo) minElo = elo;
- room.rated = minElo;
-
- if (p1) p1.mmrCache[formatid] = +p1rating.elo;
- if (p2) p2.mmrCache[formatid] = +p2rating.elo;
- room.update();
- } catch (e) {
- room.addRaw(`There was an error calculating rating changes.`);
- room.update();
- }
- return [p1score, p1rating, p2rating];
+ return [p1score, data?.p1rating, data?.p2rating];
}
/**
@@ -175,8 +145,12 @@ export class LadderStore {
}
/**
* Calculates Elo based on a match result
+ *
*/
- private calculateElo(previousUserElo: number, score: number, foeElo: number): number {
+ calculateElo(oldElo: number, score: number, foeElo: number): number {
+ // see lib/ntbb-ladder.lib.php in the pokemon-showdown-client repo for the login server implementation
+ // *intentionally* different from calculation in ladders-local, due to the high activity on the main server
+
// The K factor determines how much your Elo changes when you win or
// lose games. Larger K means more change.
// In the "original" Elo, K is constant, but it's common for K to
@@ -184,22 +158,20 @@ export class LadderStore {
let K = 50;
// dynamic K-scaling (optional)
- if (previousUserElo < 1200) {
+ if (oldElo < 1100) {
if (score < 0.5) {
- K = 10 + (previousUserElo - 1000) * 40 / 200;
+ K = 20 + (oldElo - 1000) * 30 / 100;
} else if (score > 0.5) {
- K = 90 - (previousUserElo - 1000) * 40 / 200;
+ K = 80 - (oldElo - 1000) * 30 / 100;
}
- } else if (previousUserElo > 1350 && previousUserElo <= 1600) {
+ } else if (oldElo > 1300) {
K = 40;
- } else {
- K = 32;
}
// main Elo formula
- const E = 1 / (1 + Math.pow(10, (foeElo - previousUserElo) / 400));
+ const E = 1 / (1 + Math.pow(10, (foeElo - oldElo) / 400));
- const newElo = previousUserElo + K * (score - E);
+ const newElo = oldElo + K * (score - E);
return Math.max(newElo, 1000);
}