Re: Mouratglou: Serena was an underachiever before working with me!
I'm not sure about "underachiever", but there's no doubt that without him she wouldn't have won half of the slams she managed to in that period. There's a high probability she would have retired around 2013-14. Also let me remind you about 2010s courts conditions that are different to 2000s. It's PM who teached Serena how to play there, without him with her old gamestyle she was exposed by some lower ranked players. So yees, he is responsible for her success.