I have no idea what fixed crawl means
It’s something for nerds of archery. Basically goes like this. Instead of hooking the string directly where the arrow nocks you “crawl” down the string below the arrow to some degree. What this does is basically allows you to set your own impact point. As you “crawl” down the string, you are pitching the arrow more downward, with the nock end coming up towards your eye, so the further you crawl down the more the nock end comes up in line with your eye so you are sighting down it more directly. You anchor in the same spot on your face every time. So how far you crawl has to do with how low your anchor point is, and your facial shape, because what matters is the distance between your eye and the arrow nock. The further below your eye the nock is, the more the arrow is pitched upward and the bigger of an arc you will be dealing with. So the lower you anchor, the further out your point on is. You have the basic understanding that the arrow rises and falls in an arc and you have a point on impact distance where when you aim the arrow directly in center of target spot, you impact there. In between that distance and the target you would have to aim somewhere below target as the arrow will rise into the target due to the pitch of the arrow. That’s gap shooting, having to hold off the target somewhere below. Obviously beyond your point on distance you’re aiming above the target. So with using a crawl, or stringwalking as they say, basically what you are doing is for any given distance you crawl down the string to some degree which reduces the pitch of the arrow and eliminates having to aim below the target and instead, you aim right in the center every time. And these stringwalkers mark up their tabs so they have marks for different distances and they just check the distance to the target, set their hook so far below the arrow nock, and make the shot. Each shot is aimed directly on target, although some set it to be aimed just below because it’s mentally tough to make a shot which the sight totally blocks the target and you want the target in your sight picture. The further down you crawl, the more the arrow is pitched downward and the closer your point on becomes, and vice versa. This is good for field archery and 3D where there’s no rush to make the shot and you can figure out the distance or you know the distance. It’s not good for hunting especially with an animal rapidly closing the distance coming in to you so these guys have come up with the fixed crawl for hunting. It blends gap shooting and string walking like so: you set up a point on distance of your choosing by crawling down the string a certain distance. So say you want a 25 yard fixed crawl, you might set your hook 1/2 inch below the bottom nock below the arrow. So now you mark that point on the string by setting a THIRD nock point there under which you hook when you draw the bow. Now you have a permanent 25 yard point on. In between that distance and the target, and then further out, you will aim above or below target (gap shooting). The big benefit of this is that your gaps are quite small now as compared to hooking the string right under the arrow. In fact with the right weight arrow and fixed crawl setup you can literally have your gaps so small that you are aiming merely a few inches below the impact point at common hunting distances. For me, I have a pretty long neck and I have to anchor fairly low on my face to keep my shoulders low and keep the load of the bow in my back. This means that the fixed crawl really solved the issue of the arrow pitch. Some guys have a short neck and can anchor with arrow literally right under eye and with that plus a really heavy arrow you could get your gaps pretty small and maybe not have to bother will all this stuff. The main thing that this all revolves around is this notion of being able to aim the arrow either right on or very close on the target. It’s way easier and far more accurate. Having a big gap with the arrow aimed way below target is detrimental to accuracy. And I also like to fool around with waxed string tie on nock points, leather tabs, and all this fussy stuff and getting a rig together that does what I need it to on target