Kinda seems like you might only be able to make simple deductions...
Perhaps, perhaps not, but is that not better than those here able to make no deductions, or others deducting something is better than that which they have never tried?
As you mention, some "slipperiness" is required for a proper glide. I would argue the optimum lubrication is provided by soap, not water.
You would argue based on what? Your use of water only at the sink, or water only in the shower, compared to soap? Or argue what is based only in your imagination as a comparison?
My argument is based on experience using all of the above, then theorizing why my best results are as they are.
Do you have a better explanation for my results, or the results of the OP?
Water on its own is usable - some people do shave without soap - but its not the norm. Most people find the extra lubrication from lather provides a better shave. Which it does.
"Most people" don't know the difference, for never having tried. Though, if you were to argue that a lather shave at the sink provides a better shave than a lather-less shave at the sink, I would agree.
The slipperiness between the face and the blade however, is usually considered a bonus.
No one complains their face becomes TOO slippery when using soap.
Again, at the sink, I would agree, but not in the shower. But people not complaining about a comparison they've never tried is hardly proof of anything.
I also agree that what
@Len is saying is technically true, just not in the context of shaving!
You would always want maximum glide possible. Your don't need control in terms of handling the DE. You don't have to make quick stops and turns.
If you don't have slippery skin (to the maximum extent), you will create a bump or a ridge in the skin right before the blade (due to drag). And this ridge is the same deal as having an improper angle of the razor - the blade will scrape the skin rather than cut the hair and glide over the skin (which would be the case with taut/slippery skin). You would inevitably damage the outer layer of the skin.
I thought this was already established science?
There may be specific cases where a lathered shave is preferable to a lather-less shower shave. Specific hair and skin type might call for it, for example. Using a straight razor might make a lathered shave more optimal.
In my case, I
always chase the closest possible BBS shave. The vast majority of people are fine with a DFS. If a DFS was good enough for me, I would agree with you, and stick almost exclusively with lather. The reason lather can be easier, especially when going for your typical DFS, is that less sensitivity is required for feeling the contours and tender points of the face; using the razor as an extension of the hand in one's sense of touch. It's simple really. Find your angle, no pressure, and zip around the face. Done. But going for a BBS... without weepers or irritation... ? That requires very subtle changes of pressure on different areas of the face that one feels by touch. Much of that sense of touch is lost when using a buffer like lather, and the glide is so slick that those subtle changes are more difficult to make accurately.
See, you are speaking of bumps, ridges, and drag that can occur when one doesn't have enough glide, and I definitely agree. Shower shaving, at least for me (and others apparently), does provide enough enough glide to prevent blade skipping (bumps, ridges, and drag), but not so much glide that subtle adjustments, and losing some sense of touch, are more difficult when one is chasing the closest possible shave.
I'm willing to accept if I'm wrong about any or all of this. But if I'm wrong, explain my results, or the OP's. Thus far I've read no explanation of these superior results, and what I have read is a critique based on no experience (or even explanation) with what is being criticized.