How is rank calculated?

[Lys]

Greed is the path to the dark side… greed leads to loss… loss leads to frustration… frustration leads to urge…urge leads to suffering!

Moreover, the chart seems not so reliable…

Wins/losses chart

I have some doubt on wins/losses chart reliability. Please see the image: 3 wins vs. weaker opponent not showing in the histogram. The same for the 2 losses vs. weaker opponents. Is it a bug? [Immagine] I noticed it since august 2017 after the changing of rating system. At that time many had doubts on the new ranks but I can’t imagine if the two tings could be related.