Theoretical question


Currently I am in process of learning as much as possible about performance before I start to work in improving my company’s website performance.

One idea came to my mind, it’s simple and it’s strange to me that nobody mentioned it anywhere(and I have read and watched many many material on the subject) so that is a sign to me that I might be wrong… but non the less I want to hear what you guys think about it…

So here it goes, for start, to make things simple, let’s assume that site follows all rules Steve Souders has on his blog,

That being said, I am intrested what is the theoretical best case scenario for increased performance with the work I will do. That includes making javascript async and maybe getting images to load after page load(maybe with this plugin + making critical inline css

With that in mind I test the current site with block for js and images + adding critical inline css and I would get theoretical best case scenario?
Meaning anything I do won’t make it better than test set up this way, it can only get worse but lowering that difference is the goal…

Maybe this is overly simplified, but this seems to me like nice way to get a quick glimpse of what your work on site performance can do.

Potentially, assuming the server-side of things is in good shape and you’re not also focused on the TTFB. Blocking the scripts and some of the images is usually a good first “what if” step even without doing the critical css bit that should give you a good idea of what is possible.