quote: The idea is that we look to it to represent skill level, but it does nothing of the sort. |
It does represent skill level. But it considers the whole history.
For a contrived example to illustrate why this sometimes gives weird results:
Imagine a player who is amazingly good at jump micro, but crap at everything else.
He attains a high ranking solely from his awesome jump micro.
Then a widget gets added to the game which automates jump micro.
The next day you play against Mr. Jump Micro and beat him soundly, gaining a whole bunch of ELO.
The next 10 people who play vs My. Jump also completely thrash him.
The game will start lowering your ELO with cause easily visible to you because it realizes that actually, beating Mr. Jump isn't as impressive as it thought and something happened to Mr. Jump to make him much less prone to winning games.