Coach Kim Hannah of Chicago, IL writes in with a question one of her students came in with: “In my abundant free time (kidding) I have tracked down some DVDs on instinctive shooting. I have noticed that when explicitly or implicitly they all shoot with a slight cant of about 15 – 20 degrees or so . . . not the straight statuesque position of Olympic archers. What do you make of this?”
I like inquisitive students and this is a good question! The answer depends on whether your audience is comprised of target shooters or bowhunters. Bowhunters tilt their bows, typically top limb to the right if right-handed for a couple of reasons. This technique, called “canting the bow” allows the archer to see more clearly the bowhunter’s prey, basically because the bow is no longer in the way. Most importantly, it allows both eyes to clearly see the target, providing the binocular vision required for accurate distance estimation.
Now traditional bowhunters, hunting this way (it is not really “instinctive” rather learned through repetition), are not estimating distance using formulas or schemes involving conscious thought but are doing it subconsciously. No matter how it is done, without binocular vision, aka both eyes wide open and able to focus on the target, our ability to estimate distance is very poor.
Now, the reason target archers do not do this is this: when you cant the bow, the bow is rotating in your hand. If your bow has a typical recurve style grip section, it is rotating around the “pivot point,” or the deepest point of the grip. This means that the arrow swings in a quite tiny arc during the cant because it is very close to the pivot point. But if you are using a bow sight, the bow sight’s aperture is swinging in a much larger arc (because it is farther from the pivot point) and you have now messed up both the windage (left-right) and elevation (up-down) connection between the arrow and sight. In other words, the sight only works correctly at the exact cant that you sighted in with. Any other cant introduces error. Since all techniques are subject to “normal variation” (sometimes the cant is more, sometimes less), we have introduced another source of variation into our shooting which makes our groups larger, not smaller.
Consequently target archers are taught to not cant their bows. Placing our bows straight up and down is a direction we can find with some accuracy and variations from it cause small errors. The more we cant the bow, the bigger the error we are talking about.
Traditional bowhunters can get away with a sizeable cant (as much as 90 degrees!), because they are not using a sight and the benefits far outweigh the tiny error introduced. This is further an acceptable technique in that bowhunters are shooting at relatively short distances compared to target archers. Back in the longbow era, typical target distances were 60, 80, and 100 yards. Most deer are taken, for example, well short of 25 yards. Shorter distances means larger errors produce smaller effects in that, once an arrow is off line, the longer it flies the farther off line it gets.
As far as instruction goes, we teach all beginners to shoot with their bows upright as we are teaching target archery. Should the student want to try traditional bowhunting, it is not so hard to learn to cant their bow.
Hope this helps!