Why do many people start the Snatch with a very upright torso?

Question

As explained there in an excellent way, performing deadlifts with a too upright trunk (or, equivalently, with hips too low) is not optimal as it puts the shoulders behind the bar, instead of above the bar. That's not optimal as the delts aren't able to hold the barbell in a partial front raise position with the load a person is supposed to use with deadlift.

However, I've seen plenty of Olympic Weightlifters assuming a very upright torso with shoulders even behind the bar during snatches. That's a tipical picture (shoulders slightly behind the bar, or anyway at a limit position I've never seen in deadlift):

I'm curious to know:

1. Which advantages this position offers for them in Snatch

2. Why loading the front delts in this way is not a concern

Answer 1

In the snatch, horizontal motion of the bar must be limited to keep from losing it behind. The hip hinge is usually the cause of most horizontal motion. Keeping the hips low allows the lifter to explode more vertically using the legs as the main driver. Letting your hips shoot up in the pull off the floor can cause too much back engagement and an arched bar path. In my personal experience, keeping the hips low can also make it easier to keep from losing balance and having your heels come off the floor in the initial part of the pull (ground to knees). In any case the optimal starting position in any lift is very personal and will depend on a lifter's strengths and weaknesses, their anatomy, as well as their technique, so you can't really generalize about hip height.

I don't really understand what your question is about the delts. Again, everyone's technique will differ a bit but IMO the delts don't really have anything to do with hip height in the starting position. The bar needs to be held close to the body throughout the snatch, basically the opposite of a front raise, so (again IMO) if your front delts are engaged, you're probably doing something wrong.