Cutting has been the single most influential factor on my fencing training (that is, sparring and interpretation) in the last 5 years. Thanks to cutting I have a no-bullshit measuring stick for whether a particular approach to a technique would lead to a viable cut for a "real fight."
Thanks to cutting practice I've scrapped several interpretations of cuts that many people still perform effectively in touch-sparring...but I don't do them anymore because I know that while a certain approach to a techinique might work great in sword-tag, it won't cut a target, or if it does cut it might get stuck in the target in a way that leaves me horribly open. Thanks to cutting practice I've been able to hone my mechanics for techniques like shielhau and krumphau for strength, speed, edge alignment, follow-through, etc. All things you can "get a way with" cheating on if you're just sparring. Cutting practice has opened my eyes to subtleties of grip, pressure, structure, and the order in which you engage different muscle groups in a way that I assume our ancestors understood but which we, as modern HEMAists, have had to re-discover.
Big cuts and "Someone on the Internet is Wrong!"
Every time pictures or videos of cutting competitions get posted to Facebook and Reddit, the validity of this type of training is questioned. How does cutting a grass mat, something stolen from the Japanese, apply to HEMA? Is it HEMA at all? Then we take into account that many criticisms of cutting come from folks watching the finals of cutting competitions such as Longpoint. Seeing as the cutting that tends to get videoed at HEMA events are the big cuts, people need to understand that those get filmed because they're impressive, not because they're a major part of cutting training.
The other thing that people tend to misunderstand about the big cuts is they're not about utility in a fight; they're about teasing out the tiny flaws that do matter in a fight. That big cut into eight mats in four double-rolls, often performed square-footed and with plenty of prep time, is looking at your ability to maintain edge alignment while in-target. So the target is larger than most anyone can cut all the way through. As a result, a fencer who can cut a single mat (not a substantial target) in a seemingly perfect vertical line can be brought to his metaphoric knees by that larger, denser, seemingly never-ending target. Imperfections in that dense target cause the cut to skew off-line, showing that the cutter isn't cutting efficiently. It also leads to the weapon getting stuck or even bent--and that has obvious application to a "real fight" when cutting into a dense target such as a human body.
In my case, there were two flaws in my "big cut" in the Longpoint 2016 cutting finals (which I didn't perform square footed on purpose this year).
The first was my actual base angle, which I thought was vertical, was actually about 5 degrees off vertical. That's a training flaw a single mat won't show me, and it's a big deal. My cut should do what I think it does, because my body should do what I tell it to do.
The second flaw was that my cut turned in the fourth double-roll. So sure, I cut cleanly through 6 mats in a row, but that last roll exposed some problem with follow-through on alignment or grip. The blade turned, scalloping at the very end. Had that been a body my sword would have stuck; thankfully the flaw wasn't bad enough to bend my sword, which is a real danger in that cut.
These are lessons that cutting is still teaching me--especially the big cuts with the least obvious correlation to fighting. In fact, some of the more obviously martially-applicable cutting feats (chasing the moving target, for example) tell me very little about my actual flaws as a cutter. So now I've taken that feedback from the big cut and I'm training based on it. I'm looking at my grip, at my stance, at how I generate power in those cuts because I want my vertical cut to actually be vertical, consistently, from start to finish. I want my cuts to be clean and to carry through without warping, because as a martial artist it's important to me that my cuts don't just touch the opponent...they cleave. Cleanly. And without bending my sword.
Note: A video of Jake performing the cut mentioned in this article can be found here, starting at the 13:35 mark.
Capital Kunst des Fechtens