I've known about the X-factor for years. I believe Jim McLain was the one who first talked about it back in the 1980s. Hideki Matsuyama is a well-conditioned professional athlete and most pro golfers spend hours in the fitness trailer working on their flexibility to allow them to move their bodies in ways the human body wasn't evolved to doing. Even at that Matsuyama's hips are not stationary. They have turned. Just not as much as the shoulders. My comment had to do with the relation of the shoulders to the torso, not the hips. As your photo shows, Matsuyama's shoulders and torso have turned as a unit.
I just got done watching the PGA championship. Unbelievable performance by Aaron Rai. Throughout the weekend, CBS used technology to measure the shoulder and hip turns of various golfers and how they compared to the Tour average. It was interesting but not of much use to me. If I tried to make that big a turn, I would end up in traction.
As they used to say when I was an avid runner, "If you want to be an elite runner, choose your parents carefully." At the elite level of all sports, genetics is the one factor that can't be overcome. My father and half-brother were both professional golfers (not tour players) and I worked at PING, but I was never better than "sometimes I break 80" due largely to vision and back problems. There are sooooo many players who are "really good" or even "really, really good" but just do not have what it takes to play at the elite level - something that's difficult to admit to yourself. I used to stand in front of a mirror and try to contort myself into Ben Hogan's positions in his
Power Golf-era swing before the bus accident. Not swinging, just standing there. I couldn't come close. When Tiger Woods was tested at the Stanford athletic department, he was off the scale in comparison to other athletes, not just golfers. Most modern instruction is for 20-year-olds and irrelevant (or harmful) for the rest of us.
Butch Harmon once said "Give me 100 six-year-olds who have never seen a golf club. I will tell you at the end of a week which of them, if any, has the potential to play tour-level golf." I also had a funny experience when I was 14. I visited my grandmother, who was a member of Kansas City Country Club. I played the course twice, thought it was harder than hell, and probably shot 97 or higher; I remember I ran out of balls the first round. Looking at the handicap sheet in the locker room, one guy had posted consistently 67-67-67-64-65 and was a +3 handicap. I asked "What's a +3 handicap?" (having no idea there even was such a thing as + handicap). The pro, Stan Thirsk, said "Oh, that means he averages several strokes under par - and the funny thing is, he's exactly the same age as you." Tom Watson. Genetics.
I always had a dream that technology would create some sort of plastic shell I could step into that would duplicate Tiger Woods' swing so I could experience what it felt like for five balls. Even those of us who worked at PING and saw pros every day agreed that it all seemed almost magical when a long-hitting pro took a swing that looked not much different from ours but the results looked jaw-droppingly different (and this was in the persimmon driver, balata ball era).