From 6ccc6df6aa8cacebb913180d9ea99512b7dc2e7e Mon Sep 17 00:00:00 2001
From: Joseph Prezioso Jr <joeprezioso@comcast.net>
Date: Thu, 31 Mar 2016 13:57:21 -0400
Subject: [PATCH] Elo calculations now account for player's Elo, relative to
 the average Elo among players

---
 .../src/nautilus/game/arcade/game/Game.java   | 81 +++++++++++++++++--
 1 file changed, 74 insertions(+), 7 deletions(-)

diff --git a/Plugins/Nautilus.Game.Arcade/src/nautilus/game/arcade/game/Game.java b/Plugins/Nautilus.Game.Arcade/src/nautilus/game/arcade/game/Game.java
index f204a2c77..b547c3439 100644
--- a/Plugins/Nautilus.Game.Arcade/src/nautilus/game/arcade/game/Game.java
+++ b/Plugins/Nautilus.Game.Arcade/src/nautilus/game/arcade/game/Game.java
@@ -1279,14 +1279,61 @@ public abstract class Game implements Listener
 			Manager.GetChat().Silence(5000, false);
 	}
 	
+	public int CalculateEloMultiplier(int currentElo, int averageElo)
+	{
+		
+		int eloDifference = averageElo - currentElo;
+		
+		if (Math.abs(eloDifference) <= 50)
+		{
+			return 0;
+		}
+		if (eloDifference >= 200)
+		{
+			return 3;
+		}
+		if (eloDifference >= 100)
+		{
+			return 2;
+		}
+		if (eloDifference > 50)
+		{
+			return 1;
+		}
+		if (eloDifference <= -200)
+		{
+			return -3;
+		}
+		if (eloDifference <= -100)
+		{
+			return -2;
+		}
+		if (eloDifference < 50)
+		{
+			return -1;
+		}
+		
+		
+		return 0;
+	}
+	
 	public void AdjustPlayerElo(List<Player> places)
 	{
+		int averageElo = 0;
+		for (Player player : UtilServer.getPlayers())
+		{
+			averageElo += Manager.getEloManager().getElo(player.getUniqueId(), GetName());
+		}
+		//average Elo of all players
+		averageElo = averageElo/places.size();
 		
 		for (Player player : UtilServer.getPlayers())
 		{
 			int currentElo = Manager.getEloManager().getElo(player.getUniqueId(), GetName());
 			int lossMultiplier = 1;
 			int sizeModifier = 3;
+			int eloMultiplier = CalculateEloMultiplier(currentElo, averageElo);
+			
 			//nobody won, add 10 points to all players
 			//Profitable enough see the match through to the end, but not enough for a stale-mate to be a more desirable outcome than 3rd place
 			if (places == null || places.isEmpty())
@@ -1300,8 +1347,8 @@ public abstract class Game implements Listener
 				if (places.size() >= 1)
 				{
 					if (player.getUniqueId() == places.get(0).getUniqueId())
-					{
-						int newElo = currentElo + 25;
+					{	
+						int newElo = currentElo + 25 + (5 * eloMultiplier);
 						Manager.getEloManager().saveElo(player.getUniqueId(), GetName(), newElo);
 					}
 				}
@@ -1309,7 +1356,7 @@ public abstract class Game implements Listener
 				{
 					if (player.getUniqueId() == places.get(1).getUniqueId())
 					{
-						int newElo = currentElo + 20;
+						int newElo = currentElo + 20 + (5 * eloMultiplier);
 						Manager.getEloManager().saveElo(player.getUniqueId(), GetName(), newElo);
 					}
 				}
@@ -1317,7 +1364,12 @@ public abstract class Game implements Listener
 				{
 					if (player.getUniqueId() == places.get(2).getUniqueId())
 					{
-						int newElo = currentElo + 15;
+						if (eloMultiplier < -2)
+						{
+							eloMultiplier = -2;
+						}
+						
+						int newElo = currentElo + 15 + (5 * eloMultiplier);
 						Manager.getEloManager().saveElo(player.getUniqueId(), GetName(), newElo);
 					}
 					
@@ -1326,7 +1378,12 @@ public abstract class Game implements Listener
 				{
 					if (player.getUniqueId() == places.get(5).getUniqueId())
 					{
-						int newElo = currentElo - 5;
+						if(eloMultiplier > 1)
+						{
+							eloMultiplier = 0;
+						}
+						
+						int newElo = currentElo - 5 + (5 * eloMultiplier);
 						Manager.getEloManager().saveElo(player.getUniqueId(), GetName(), newElo);
 					}
 				}
@@ -1334,7 +1391,12 @@ public abstract class Game implements Listener
 				{
 					if (player.getUniqueId() == places.get(6).getUniqueId())
 					{
-						int newElo = currentElo - 10;
+						if(eloMultiplier > 2)
+						{
+							eloMultiplier = 2;
+						}
+						
+						int newElo = currentElo - 10 + (5 * eloMultiplier);
 						Manager.getEloManager().saveElo(player.getUniqueId(), GetName(), newElo);
 					}
 				}
@@ -1345,7 +1407,12 @@ public abstract class Game implements Listener
 					{
 						if (player.getUniqueId() == places.get(places.size() - sizeModifier).getUniqueId())
 						{
-							int newElo = currentElo - (5 * lossMultiplier);
+							if(eloMultiplier > lossMultiplier)
+							{
+								eloMultiplier = lossMultiplier;
+							}
+							
+							int newElo = currentElo - (5 * lossMultiplier) + (5 * eloMultiplier);
 							Manager.getEloManager().saveElo(player.getUniqueId(), GetName(), newElo);
 							
 							if(sizeModifier >= 1)