Implementation of Elo's rating algorithm in PHP.
The final rating is based on the current scores(win or loss) of A and B, and the one with highest current rating loses more points to the other when lost,than he could gain if wins.same the other way.
for example,
Current Rating of A = 2000
Current Rating of B = 1700
so,
Final Rating of A --> 2004.8313458308 (Gains 5 points from B)
Final Rating of B --> 1695.1686541692 (Loses 4 points to A)
and
Final Rating of A --> 1972.8313458308 (Loses 27 points to B)
Final Rating of B --> 1727.1686541692 (Gains 28 points from A)