in case you just took the winratios per day and tried averaging them out... that's statistically useless. for example i don't know whether it was a bug or not, but on oct. 31st according to coh2chart.com there were 4 (!) ostheer games played all day, all wins. so suddenly you have a single day winratio of 100%. so, let's assume we average it out over the week, and the 6 other days have a perfectly balanced 50% winrate, the weeks average would be over 57%, with just 1 outlier. if you want statistically relevant data, use games played and winratio to figure out the amount of wins per game by adding both numbers up. you'll see that the numbers for axis are WAY lower now (if you look at ostheer for example, it is very visible that every day where ostheer has a high winratio coincides with very low amount of games played).
yeah, sorry to burst your bubble ;-)
Good point about accurate statistics! However, that doesn't change that OKW win rates are way up post patch. In team games, Ostheer percentages are also rising probably because of OKW carrying.