app1Elo = 1600;
app2Elo = 1200;
kFactor = 20;

transformed1 = Math.pow(10, (app1Elo/400)); // Transformed rating of 100,000
transformed2 = Math.pow(10, (app2Elo/400)); // Transformed rating of 10,000

expected1 = transformed1 / (transformed1 + transformed2); // Expected score of ~0.91
expected2 = transformed2 / (transformed1 + transformed2); // Expected score of ~0.09

if(winner == APP1){
	app1Elo += (kFactor * (expected2)); // Increased by 2 to ~1602
	app2Elo -= (kFactor * (expected2)); // Decreased by 2 to ~1198
}else{
	app1Elo -= (kFactor * (expected1)); // Decreased by 18 to ~1588
	app2Elo += (kFactor * (expected1)); // Increased by 18 to ~1218
}