Dear Axel,
Yes, I think the straight gaze at address has a beneficial effect on the full swing. While I'm not a full-swing instructor, I've been told a number of times that people I've taught about the straight gaze have used it to good effect in the full swing.
I think there are probably two reasons the straight gaze at address helps in the full swing. First, it helps the body leran or teach itself where the target is located for puposes of making the swing to send the ball to the target. This sort of body-movement targeting is different than "looking" to "see" or "view" a target -- it is about orienting the body and its forthcoming mpvement to the target.
Second, the base of the neck used at address with a straight-out gaze is pretty much the same plane as the swing. If you stood in one of those large circular tubes used as a swing-plane trainer, the plane of the device is about the same as that of the base of the neck at address when looking down at a ball. This body orientation in the neck-shoulder area helps the body make the correct swing.
You still have to setup square to the ball with the body and clubface aimed at the target. It's just that in aiming or orienting the body, you are really aiming the whole swing as it occurs in time. The gaze helps get the body oriented in a good position for an accurate swing. The same as in putting.
Cheers!
Geoff Mangum
Putting Theorist and Instructor
PuttingZone.com
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