feat: ✨ added elo esstimation feature

Author: Theprathamshah

src/lib/engine/helpers/estimateElo.ts

@@ -0,0 +1,55 @@
+import { ceilsNumber } from "@/lib/math";
+import { EstimatedElo, PositionEval } from "@/types/eval";
+
+export const estimateEloFromEngineOutput = (positions: PositionEval[]): EstimatedElo => {
+    try {
+        
+        if (!positions || positions.length === 0) {
+            return { white: null, black: null };
+        }
+
+        let totalCPLWhite = 0;
+        let totalCPLBlack = 0;
+        let moveCount = 0;
+        let previousCp = null;
+        let flag = true;
+        for (const moveAnalysis of positions) {
+            if (moveAnalysis.lines && moveAnalysis.lines.length > 0) {
+
+                const bestLine = moveAnalysis.lines[0];
+                if (bestLine.cp !== undefined) {
+                    if(previousCp !== null) {
+                        const diff = Math.abs(bestLine.cp - previousCp);
+                        if (flag){
+                            totalCPLWhite += ceilsNumber(diff, -1000, 1000);
+                        }
+                        else {
+                            totalCPLBlack += ceilsNumber(diff, -1000, 1000);
+                        }
+                        flag = !flag;
+                        moveCount++;
+                    }
+                    previousCp = bestLine.cp;
+                    
+                }
+            }
+        }
+
+        if (moveCount === 0) {
+            return { white: null, black: null };
+        }
+
+        const averageCPLWhite = totalCPLWhite / Math.ceil(moveCount/2);
+        const averageCPLBlack = totalCPLBlack / Math.floor(moveCount/2);
+
+        const estimateElo = (averageCPL: number) => 3100 * Math.exp(-0.01 * averageCPL);
+
+        const whiteElo = estimateElo(Math.abs(averageCPLWhite));
+        const blackElo = estimateElo(Math.abs(averageCPLBlack));
+
+        return { white: whiteElo, black: blackElo };
+    } catch (error) {
+        console.error("Error estimating Elo: ", error);
+        return { white: null, black: null };
+    }
+}

src/lib/engine/uciEngine.ts

@@ -1,5 +1,6 @@
 import { EngineName } from "@/types/enums";
 import {
+  EstimatedElo,
   EvaluateGameParams,
   EvaluatePositionWithUpdateParams,
   GameEval,
@@ -14,6 +15,7 @@ import { getIsStalemate, getWhoIsCheckmated } from "../chess";
 import { getLichessEval } from "../lichess";
 import { getMovesClassification } from "./helpers/moveClassification";
 import { EngineWorker } from "@/types/engine";
+import { estimateEloFromEngineOutput } from "./helpers/estimateElo";
 
 export class UciEngine {
   private worker: EngineWorker;
@@ -141,7 +143,7 @@ export class UciEngine {
 
     await this.sendCommands(["ucinewgame", "isready"], "readyok");
     this.worker.uci("position startpos");
-
+    
     const positions: PositionEval[] = [];
     for (const fen of fens) {
       const whoIsCheckmated = getWhoIsCheckmated(fen);
@@ -180,17 +182,19 @@ export class UciEngine {
         99 - Math.exp(-4 * (fens.indexOf(fen) / fens.length)) * 99
       );
     }
-
+    
     const positionsWithClassification = getMovesClassification(
       positions,
       uciMoves,
       fens
     );
     const accuracy = computeAccuracy(positions);
-
+    const estimatedElo: EstimatedElo = estimateEloFromEngineOutput(positions);
+    
     this.ready = true;
     return {
       positions: positionsWithClassification,
+      estimatedElo,
       accuracy,
       settings: {
         engine: this.engineName,

src/sections/analysis/panelBody/analysisTab/accuracies.tsx

@@ -1,8 +1,11 @@
 import { Grid2 as Grid, Typography } from "@mui/material";
 import { useAtomValue } from "jotai";
 import { gameEvalAtom } from "../../states";
+type props = {
+  params: "accurecy" | "rating";
+}
 
-export default function Accuracies() {
+export default function Accuracies(props: props) {
   const gameEval = useAtomValue(gameEvalAtom);
 
   if (!gameEval) return null;
@@ -24,11 +27,10 @@ export default function Accuracies() {
         fontWeight="bold"
         border="1px solid #424242"
       >
-        {`${gameEval?.accuracy.white.toFixed(1)} %`}
+        { props.params === "accurecy" ? `${gameEval?.accuracy.white.toFixed(1)} %` : `${Math.round(gameEval?.estimatedElo.white as number)}`}
       </Typography>
 
-      <Typography align="center">Accuracies</Typography>
-
+      <Typography align="center">{ props.params === "accurecy" ?  "Accuracies" : "Estimated Elo"}</Typography>
       <Typography
         align="center"
         sx={{ backgroundColor: "black", color: "white" }}
@@ -38,7 +40,7 @@ export default function Accuracies() {
         fontWeight="bold"
         border="1px solid #424242"
       >
-        {`${gameEval?.accuracy.black.toFixed(1)} %`}
+        {props.params === "accurecy" ? `${gameEval?.accuracy.black.toFixed(1)} %` : `${Math.round(gameEval?.estimatedElo.black as number)}`}
       </Typography>
     </Grid>
   );

src/sections/analysis/panelBody/analysisTab/index.tsx

@@ -57,8 +57,9 @@ export default function AnalysisTab(props: GridProps) {
           : { overflow: "hidden", overflowY: "auto", ...props.sx }
       }
     >
-      <Accuracies />
-
+      <Accuracies params={"accurecy"}/>
+      <Accuracies params={"rating"}/>
+      
       <MoveInfo />
 
       <Opening />

src/types/eval.ts

@@ -21,6 +21,10 @@ export interface Accuracy {
   black: number;
 }
 
+export interface EstimatedElo {
+  white: number | null;
+  black: number | null;
+}
 export interface EngineSettings {
   engine: EngineName;
   depth: number;
@@ -31,6 +35,7 @@ export interface EngineSettings {
 export interface GameEval {
   positions: PositionEval[];
   accuracy: Accuracy;
+  estimatedElo: EstimatedElo;
   settings: EngineSettings;
 }