Merge pull request #49 from codergautam/futurepear

elo formula change

.gitignore

@@ -21,6 +21,10 @@
 .DS_Store
 *.pem
 logs
+
+#visual studio
+.vs
+
 # debug
 npm-debug.log*
 yarn-debug.log*

components/utils/eloSystem.js

@@ -1,28 +1,33 @@
 // Constants
-const K = 32; // Scaling factor for Elo rating changes
+const K = 50; // Scaling factor for Elo rating changes
 const c = 500; // Factor for expected outcome calculation
 const Rmin = 100; // Minimum Elo rating to avoid negative experiences
 export const Ra0 = 1000; // Initial Elo rating for new players
+
 const V = 10; // Bonus factor for victories
 const L = 5; // Additional scaling factor for score differences
+
 const maxElo = 10000;
+const exponentBase = 1.7;
 
 // Function to calculate expected outcome
 function expectedOutcome(Ra, Rb) {
-  const Qa = Math.pow(10, Ra / c);
-  const Qb = Math.pow(10, Rb / c);
+  const Qa = Math.pow(exponentBase, Ra / c);
+  const Qb = Math.pow(exponentBase, Rb / c);
   return Qa / (Qa + Qb);
 }
 
 // Function to update Elo rating
-function updateElo(Ra, Rb, Sa, Pa, Pb) {
+function updateElo(Ra, Rb, Pa, Pb) {
   const Ea = expectedOutcome(Ra, Rb);
-  const scoreFactor = Pa / (Pa + Pb);
-  const victoryBonus = Sa * V;
-  let gainedElo = K * (Sa - Ea) + L * scoreFactor + victoryBonus;
+
+  //https://www.desmos.com/calculator/mwnadmf8e0 
+  let gainedElo = K * (Pa - Ea - 0.5) + 34 - 3 * Pa;
+  if(Pa === 0)
+    gainedElo = Math.min(0, gainedElo); //curve pokes above 0 at the left side
 
   // Quadruple the gained Elo if the player wins and their rating is below 2000
-  if (Sa === 1 && Ra < 2000) {
+  if (Pa === 1 && Ra < 2000) {
     gainedElo *= 4;
   }
 
@@ -31,11 +36,11 @@ function updateElo(Ra, Rb, Sa, Pa, Pb) {
 }
 
 export default function calculateOutcomes(player1Rating, player2Rating, winner) {
-  const player1Outcome = winner === 1 ? 1 : winner === 0.5 ? 0.5 : 0;
+  const player1Outcome = winner === 1 ? 1 : winner === 0.5 ? 0.5 : 0; //1 if player1 wins
   const player2Outcome = 1 - player1Outcome;
 
-  const newRating1 = updateElo(player1Rating, player2Rating, player1Outcome, player1Outcome, player2Outcome);
-  const newRating2 = updateElo(player2Rating, player1Rating, player2Outcome, player1Outcome, player2Outcome);
+  const newRating1 = updateElo(player1Rating, player2Rating, player1Outcome, player2Outcome);
+  const newRating2 = updateElo(player2Rating, player1Rating, player1Outcome, player2Outcome);
 
   return { newRating1, newRating2 };
 }