diff --git a/src/client/gameLoop.ts b/src/client/gameLoop.ts
index b8c7cafd..1b8d212d 100644
--- a/src/client/gameLoop.ts
+++ b/src/client/gameLoop.ts
@@ -1,5 +1,5 @@
 
-import { gc } from "./global.js";
+import { gc, clientInfo } from "./global.js";
 
 let actual_time: number = Date.now();
 let last_time: number;
@@ -7,17 +7,31 @@ let delta_time: number;
 
 function gameLoop()
 {
-	/*
-		// I try to clear only what need to be update.
-		// Will revert to clear() all if not satisfactory.
-		pong.clear();
-	*/
 	last_time = actual_time;
 	actual_time = Date.now();
 	delta_time = (actual_time - last_time) / 1000;
 
+	// interpolation
+	// console.log(`dir.y: ${clientInfo.opponent.dir.y}, pos.y: ${clientInfo.opponent.pos.y}, opponentNextPos.y: ${clientInfo.opponentNextPos.y}`);
+	if (clientInfo.opponent.dir.y != 0 ) {
+		opponentInterpolation(delta_time);
+	}
+
 	// client prediction
 	gc.ball.moveAndBounce(delta_time, [gc.wallTop, gc.wallBottom, gc.playerLeft, gc.playerRight]);
 }
 
+function opponentInterpolation(delta: number)
+{
+	// interpolation
+	clientInfo.opponent.moveAndCollide(delta, [gc.wallTop, gc.wallBottom]);
+
+	if ((clientInfo.opponent.dir.y > 0 && clientInfo.opponent.pos.y > clientInfo.opponentNextPos.y)
+	||  (clientInfo.opponent.dir.y < 0 && clientInfo.opponent.pos.y < clientInfo.opponentNextPos.y))
+	{
+		clientInfo.opponent.dir.y = 0;
+		clientInfo.opponent.pos.y = clientInfo.opponentNextPos.y;
+	}
+}
+
 export {gameLoop}
diff --git a/src/client/ws.ts b/src/client/ws.ts
index e2d76537..ae4cc2e3 100644
--- a/src/client/ws.ts
+++ b/src/client/ws.ts
@@ -8,6 +8,7 @@ import { RacketClient } from "./class/RectangleClient.js";
 import { repeatInput } from "./handleInput.js";
 import { soundRoblox } from "./audio.js"
 import { sleep } from "./utils.js";
+import { Vector, VectorInteger } from "../shared_js/class/Vector.js";
 
 const wsPort = 8042;
 const wsUrl = "ws://" + document.location.hostname + ":" + wsPort + "/pong";
@@ -17,6 +18,8 @@ class ClientInfo {
 	id = "";
 	side: en.PlayerSide;
 	racket: RacketClient;
+	opponent: RacketClient;
+	opponentNextPos: VectorInteger;
 }
 
 export const clientInfo = new ClientInfo();
@@ -43,12 +46,17 @@ function preMatchListener(this: WebSocket, event: MessageEvent) {
 			break;
 		case en.EventTypes.matchmakingComplete:
 			clientInfo.side = (<ev.EventMatchmakingComplete>data).side;
-			if (clientInfo.side === en.PlayerSide.left) {
+			if (clientInfo.side === en.PlayerSide.left)
+			{
 				clientInfo.racket = gc.playerLeft;
+				clientInfo.opponent = gc.playerRight;
 			}
-			else if (clientInfo.side === en.PlayerSide.right) {
+			else if (clientInfo.side === en.PlayerSide.right)
+			{
 				clientInfo.racket = gc.playerRight;
+				clientInfo.opponent = gc.playerLeft;
 			}
+			clientInfo.opponentNextPos = new VectorInteger(clientInfo.opponent.pos.x, clientInfo.opponent.pos.y);
 			clientInfo.racket.color = "darkgreen"; // for testing purpose
 			socket.send(JSON.stringify( new ev.ClientEvent(en.EventTypes.clientPlayerReady) ));
 			matchmakingComplete();
@@ -66,7 +74,7 @@ function inGameListener(event: MessageEvent)
 	const data: ev.ServerEvent = JSON.parse(event.data);
 	switch (data.type) {
 		case en.EventTypes.gameUpdate:
-			// setTimeout(gameUpdate, 1000, data as ev.EventGameUpdate); // artificial latency for testing purpose
+			// setTimeout(gameUpdate, 500, data as ev.EventGameUpdate); // artificial latency for testing purpose
 			gameUpdate(data as ev.EventGameUpdate);
 			break;
 		case en.EventTypes.scoreUpdate:
@@ -82,14 +90,36 @@ function gameUpdate(data: ev.EventGameUpdate)
 {
 	console.log("gameUpdate");
 
-	gc.playerLeft.pos.y = data.playerLeft.y;
-	gc.playerRight.pos.y = data.playerRight.y;
-	
 	gc.ball.pos.assign(data.ball.x, data.ball.y);
 	gc.ball.dir.assign(data.ball.dirX, data.ball.dirY);
 	gc.ball.speed = data.ball.speed;
+	if (clientInfo.side === en.PlayerSide.left) {
+		clientInfo.racket.pos.assign(clientInfo.racket.pos.x, data.playerLeft.y);
+	}
+	else if (clientInfo.side === en.PlayerSide.right) {
+		clientInfo.racket.pos.assign(clientInfo.racket.pos.x, data.playerRight.y);
+	}
 
-	repeatInput(data.lastInputId); // server reconciliation
+	// interpolation
+	clientInfo.opponent.pos.assign(clientInfo.opponentNextPos.x, clientInfo.opponentNextPos.y);
+	if (clientInfo.side === en.PlayerSide.left) {
+		clientInfo.opponentNextPos.assign(clientInfo.opponent.pos.x, data.playerRight.y);
+	}
+	else if (clientInfo.side === en.PlayerSide.right) {
+		clientInfo.opponentNextPos.assign(clientInfo.opponent.pos.x, data.playerLeft.y);
+	}
+
+	clientInfo.opponent.dir = new Vector(
+		clientInfo.opponentNextPos.x - clientInfo.opponent.pos.x,
+		clientInfo.opponentNextPos.y - clientInfo.opponent.pos.y
+	);
+
+	if (Math.abs(clientInfo.opponent.dir.x) + Math.abs(clientInfo.opponent.dir.y) !== 0) {
+		clientInfo.opponent.dir = clientInfo.opponent.dir.normalized();
+	}
+
+	// server reconciliation
+	repeatInput(data.lastInputId);
 }
 
 function scoreUpdate(data: ev.EventScoreUpdate)
diff --git a/src/shared_js/class/Rectangle.ts b/src/shared_js/class/Rectangle.ts
index b8fdeb75..3fc10310 100644
--- a/src/shared_js/class/Rectangle.ts
+++ b/src/shared_js/class/Rectangle.ts
@@ -42,9 +42,7 @@ class MovingRectangle extends Rectangle implements Moving {
 		this.speed = baseSpeed;
 	}
 	move(delta: number) { // Math.floor WIP until VectorInteger debug
-		// console.log("delta: "+ delta);
-		// console.log("speed: "+ this.speed);
-		// console.log("speed*delta: "+ this.speed * delta);
+		// console.log(`delta: ${delta}, speed: ${this.speed}, speed*delta: ${this.speed * delta}`);
 		this.pos.x += Math.floor(this.dir.x * this.speed * delta);
 		this.pos.y += Math.floor(this.dir.y * this.speed * delta);
 	}