Context: http://www.goratings.org/ http://www.goratings.org/ An interesting thing about that rating site is that it uses Whole-History Rating, a system develop

Context: http://www.goratings.org/ http://www.goratings.org/ An interesting thing about that rating site is that it uses Whole-History Rating, a system developed by Remi Coulom which takes the entire match history into account. After the Sedol vs. AlphaGo games, you could reasonably ask if Sedol was on top of his game, or if his losses were in part a product of a declining rating of his own. WHR effectively considers this possibility, and the similar possibility in all matches - you could say the long-term impact of a match doesn't stabilize after both participants have played a few more games. AlphaGo has been steadily climbing in this rating. Sedol doesn't appear to be in decline, in fact he had an 8-win streak right after the AlphaGo matches (ended by Gu Li just recently).