Adaptations

 It's not uncommon to see someone say they're "adapting" a historical system to suit their own needs with their fencing. On the surface, this sounds like a reasonable thing to do: after all, we're all different and we'll all need a tailored approach. The problem with this is that while true, it's also definitely not true. How can that be?

The truth of the matter is that the overwhelming majority of us have skeletons that are more or less identical in shape, function, and proportion. While it's true that we each have unique features, our characteristics are like our DNA: 99.9% identical, 0.1% variant. 

How silly it seems to get hung up on the 0.1% that's different!

This is not to say those differences can't or don't include important information-- we can all easily agree that a several extra inches in reach create an advantage. However, it's safe to say that human bodies are mostly very similar to one another, and thus there are a very large number of generalizations that can be made with accuracy (and precision!).

When learning to fence, it's best to prioritize the parts that fall into the 99.9% of cases and make fine adjustments for the 0.1% only when necessary. You may need to make some judgment calls here, but odds are your hand and my hand work so similarly that the effect size of any difference is negligible, for example. Thus, given a sword that's appropriately sized, we ought to hold and operate it with equal similarity. A meaningful need to adapt this to an individual would only come up if the individual has a meaningful difference, e.g. if I were missing my index finger, I'd have to adapt a closed-key grip to something else. 

So, how does this connect to claims of adapting historical systems? Almost everyone I see making this claim is dealing with the 0.1% side of things and heavily ignoring the 99.9% of the system that makes it a system. Systems, by definition, are fully coherent and integrated approaches of method-- they cannot be handled piecemeal or they don't work. To meaningfully adapt a system, it's necessary to deeply understand what makes it work. Change up too much of that 99.9% and instead of a human, you have a chimpanzee. The core matters, and understanding that core and adhering to it is what allows for adaptation and variation in the remaining 0.1%. 

Learn and perform the systems by rote, and then work on significant adaptations. Odds are, you'll change a lot less than you would have if you'd gone in from a position of ignorance.