// Winner is either 0 or 1 or 2
public void CalculateNewRating(int rating1, int rating2, GameResult winner, out int newRating1, out int newRating2)
{
int diff = Math.Abs(rating1 - rating2);
RatingLookupEntry lookup = RatingLookup.Where(entry => entry.Low <= diff && entry.High >= diff).FirstOrDefault();
newRating1 = rating1;
newRating2 = rating2;
if (lookup != null)
{
if (winner == GameResult.Player1Wins)
{
if (rating1 > rating2)
{
newRating1 = rating1 + lookup.HighBoardGains;
newRating2 = rating2 - lookup.HighBoardGains;
}
else
{
newRating1 = rating1 + lookup.LowBoardGains;
newRating2 = rating2 - lookup.LowBoardGains;
}
}
else if (winner == GameResult.Player2Wins)
{
if (rating2 > rating1)
{
newRating1 = rating1 - lookup.HighBoardGains;
newRating2 = rating2 + lookup.HighBoardGains;
}
else
{
newRating1 = rating1 - lookup.LowBoardGains;
newRating2 = rating2 + lookup.LowBoardGains;
}
}
else // Draw
{
if (rating1 > rating2)
{
newRating1 = rating1 - lookup.DrawHighLosesLowGains;
newRating2 = rating2 + lookup.DrawHighLosesLowGains;
}
else
{
newRating1 = rating1 + lookup.DrawHighLosesLowGains;
newRating2 = rating2 - lookup.DrawHighLosesLowGains;
}
}
}
}
private RatingCalculator()
{
RatingLookup = new List <RatingLookupEntry>();
RatingLookup.Add(new RatingLookupEntry {
Low = 0, High = 12, HighBoardGains = 16, LowBoardGains = 16, DrawHighLosesLowGains = 0
});
for (int i = 1; i <= 14; i++)
{
RatingLookupEntry entry = RatingLookup[i - 1];
int low = entry.High + 1;
int high = low + 24;
int hbg = entry.HighBoardGains - 1;
int lbg = entry.LowBoardGains + 1;
int draw = entry.DrawHighLosesLowGains + 1;
RatingLookup.Add(new RatingLookupEntry {
Low = low, High = high, HighBoardGains = hbg, LowBoardGains = lbg, DrawHighLosesLowGains = draw
});
RatingLookup[RatingLookup.Count - 1].High = 2000;
}
}