I've always believed that after transition, the swing was basically automatic (or should be). The only way to groove a new downswing pattern is to work on it specifically and very slowly. 

I agree...there is no way that you could fix anything in any given swing in that short a period of time.  He's good....but he aint that good !!

I recently saw an interview about Jack's 1-iron a Pebble Beach and think he said he made a correction from the top when he felt he had taken it back too far inside or something.

One teaching pro I have worked with makes solid use of video swing analysis. Although he promotes the benefits of using tech properly, he gave me this one caution:

"Sooner or later, you just have to step up there and hit the ball!" 

"...step up there and hit the ball..." promotes the idea that you can only plan so much for a golf shot. It was meant to support the idea that beyond A5, a given golf swing is a done deal.

As a 20+ HDCP golfer, I struggle with overthinking shots. I play better when I quickly survey the situation, check my alignment and hit the ball... "trust your training, commit to the shot"... not worry about trying to troubleshoot potential errors during the downswing.

Agreed. This where I see the importance of the setup snd the backswing... Properly done, we then have a chance for a good swing and successful impact. The only swing thought adjustment might be to shift more weight forward. For me, it's constantly thinking about my right elbow. However, all that occurs BEFORE the start of the downswing. 

On this post... The one thing I learned through TST is that feels are not real. And, there is a difference between touring and teaching pros. The touring pros may say they do something in an interview, but what they are sometimes describing...is a feel tht they have. And what they actually do in reality is something different.

One hears that frequently from golf commentators ... "he tried to save the shot just before impact, Johnny" ... I always wondered "how do they do that?" The downswing takes place in practically the blink of an eye... does the body sense something is wrong from its training and self-correct? I thought it was incredible. Now, like other fantastical events, it is just that ... a fantasy from a commentator or a pro thinking they are saving shots ... I wonder if some pros think they must be able to save a shot to boost themselves.

I'd be a bit more cautious about saying Tiger is wrong.

If we presume that the instruction from "mind" to "nervous system" begins at the moment the player has the conscious realization of the fault, then yes - iacas's assertion is correction. The nervous system requires fixed amounts of time for impulses to conduct, and Tiger is subject to the same limits as any of us. In other words, what you are saying is that if you consciously instruct your body make a correction that requires 50 milliseconds to accomplish, but there are only 10 milliseconds remaining until the clubhead hits the ball, your correction simply won't happen. This is what I believe you are saying.

Yet, Tiger and many other golfers insist they can "save" shots, at various stages of the swing. I've seen good players successfully do the "draw - fade" challenge (where you tell them mid-swing what shape you want, and they execute it) when the instruction seems to come too late in the swing.

How do they do it? How can they violate human neurophysiology? The answer is that they don't actually violate human physiology, it just seems that they do.  

The vast majority of what our brains do is not within our conscious awareness. What I would hypothesize is going on in these swings is that Tiger's body senses the error early enough in the swing and automatically makes the correction, in enough time for the correction to actually work, but his conscious awareness of the process lags behind the actual impulses. In other words, by the time he becomes aware of the need for correction, his body's automatic circuits have already made the diagnosis and executed the correction. Just as we only "feel" impact well after the ball has left the clubface, it is possible - probable, actually - that Tiger's conscious experience of a swing fault occurs well after his body has actually sensed or registered the error.....possibly giving him plenty of time to fix the error. This hypothesis requires the possibility that we have ingrained, pre-learned movement patterns that our brain can execute without our actually consciously thinking of it. I think there is a huge body of research supporting that this is precisely how we execute most skilled motor movements, like the golf swing.

No doubt my memory of the draw fade challenge is subjective....it's not quite the same as Tiger's assertion. There is a hard limit to the time in the swing when you are capable of following a verbal command, and that time likely cannot be much after the start of the forward movement of the club.

But your second assertion, "Right...which means...Tiger is wrong..." depends on how you define a correction, etc.

Just as there is a lag between when consciousness "wants" to do something and when the message gets to the muscles, there is a lag between when the nervous system physically "senses" something and when that sensation reaches conscious awareness.

Neural pathways aren't a single chain of events; there are multiple systems acting in parallel. As the message of the error is making it's way to his consciousness, the "correction" could also be automatically being triggered by direct, non-conscious connections in his brain's movement system.  

By the time he realizes the problem (maybe just before impact), he has already fixed it. It just appears, to his consciousness, that he has only just NOW discovered it and needs to do something.

Now, if you want to say "that's right....he's wrong, he didn't fix just before impact...as you say, he fixes it earlier" of course that's true. But the key point is that I am emphasizing that in these situations, he does in fact make a correction in the swing. The implication of saying "Tiger is wrong" is that he thinks he altered his swing, but in reality he doesn't, because his timeline doesn't compute. I'm saying, it's entirely possible - likely even - that in those situations, he does, in fact, make a change in his swing. It's just that the latency of the process fools him into thinking he made the change at the last moment. In reality, he made it much earlier.

Regarding your question of how fast an automatic response can be, I think again a key point is that the brain is a parallel processing unit, not a serial, one step at a time processor. Millions of things are going on at once.

And I know practically nothing of real research in the area. But I do know that much of animal movement in behavior involves automatic, stereotyped learned movement patterns, and that the brain is constantly anticipating things about a situation, and is prepared for a huge variety of variance. If it weren't, we wouldn't be able to walk on anything but a perfect surface without staring down at the ground and planning every step.

I think a high level golfer like Tiger not only has less overall variance in his swing patterns, but his brain has learned and anticipates all the right and wrong patterns for any given shot. So what seems like a phenomenal reaction to something isn't really that....it is simply his body's learned ability to anticipate all the possible pitfalls, and apply the appropriate corrections.