After staying silent for a long time, I’ve organized my thoughts and resurfaced to fulfill my previous promise: to turn in my homework—I’m hoping for an “Essence” post (not being arrogant, just that this is a summary of five years’ experience, which I believe might be useful to fellow ski enthusiasts who love the sport and are self-taught).  Here, I’d first like to talk about the commonalities and differences among Japanese performance-style carving, European/American travel-style skiing, and competitive carving. We can decide what we want based on our own physical conditions and preferences.
           1. Japanese Carving:
            ａ. Dual-axis theory (the shoulders, hips, knees, and ankles on both sides of the body are divided into two axes, with one side extending and the other flexing to create left-right shifts in the center of gravity)
            ｂ. Rotation (rotation of the knees, hips, and ankles; full-body rotation)
            ｃ. Maintaining the force line from the outside foot to the inside shoulder (when centrifugal force occurs, the inside edge of the lower ski on the downhill side digs in to maintain a force line that runs through the shoulder joint on the opposite side)
            ｄ. Parallel alignment of the shoulder line, hip line, and edge angle (the line connecting both shoulder joints, both hip joints, and both ski edges)
            2. European/American Travel-Style:
            ａ. Emphasis on the center of gravity (don’t lean back, keep the body posture in a lightning shape, with the upper body parallel to the calves)
             b. Stability of the upper body posture
             c. Bending the body toward the downhill side during the turn, pressing and locking the edge of the downhill ski
             d. Coordinating the body to integrate the movements of both skis
            3. Competitive Carving:
             a. Stability of the upper body (avoid leaning the shoulders left or right, avoid twisting the torso, keep your chin always pointing at the zipper of your ski suit)
            ｂ. Large left-right movements below the hips—bigger is better (achieve speed control through turns, complete gate crossings)
             c. Always facing the fall line downhill
             d. Tucking the hips up and pushing the pelvis forward (fuck up!, the coach’s exact words—men will understand, or think of the horseback riding motion of pushing the wave)
             e. Show your chest (if you’re a pretty girl, show me your bra!, don’t hunch your back)
            ｆ. Achieve full edge contact, no snow scraping
             g. The movement trajectory of the upper body resembles the crenellations of a city wall (a sinusoidal wave pattern based on the fall line)

Commonalities: Center of gravity, stability of the upper body, integration of both feet.
Differences: The Japanese style emphasizes maintaining the force line from the outside foot to the inside shoulder, having the shoulder line, hip line, and ski edges parallel, a pronounced shoulder lean during wide turns, arms extended like a bow, making the skier appear as if carrying a cross, with slightly bent knees on the downhill leg. Upper and lower body integration leads to noticeable rotation of the whole body.
               European/American travel-style: Medium to high stance, relaxed upper body, naturally hanging arms, separation of upper and lower body, a neutral position with the upper body tilted toward the downhill (this is not considered counter-flexion). The outside ski carves into the snow surface with pressure applied to maintain stability. Newer techniques don’t emphasize extension and downward pressure as much. The body’s center of gravity is always forward, aligned with the tip of the ski.
               Competitive carving: No distinction between national schools or styles, all the same. Requires separation of upper and lower body, the upper body stays completely still while the lower body moves left and right as much as possible to achieve extension and downward pressure, controlling the size and speed of the turns. At the same time, the hips are tucked up and the waist pushed forward, with no special emphasis on the uphill leg.
   Personal experience:
   I haven’t paid much attention to the European/American travel-style, but it seems to focus more on the rationality of center of gravity movement and the synchronization and integration of both feet. There are no exaggerated or overly large movements, just smooth and natural. The Japanese style has an overly rigid upper body, but with less rotation in the knees and ankles, it’s simpler to learn, easier to get started with, less prone to injury, and causes less joint wear. Competitive carving demands the highest stability in the upper body, along with strong thigh muscle power and core strength.
         Seeing some of the previous physics formulas, skiing has been overcomplicated. It’s a practical process, and the issue to solve is simple: moving the body left and right, and forward and backward.