I have recently been attending the sessions at the Twin Towers Wrestling Club at the Hamilton Fish Rec Center here in NYC. Is part of the Parks Department activities, and there's usually about a 60-40 split between what I call "pin" wrestling and submission grappling/jiu jitsu. On a recent week I spent most of the session just going and going and going with a guy with unlimited energy and good skills. Then that weekend I put my armor back on and went to the local SCA armored swordfighting practice at the Brooklyn Army Terminal (first time in months).
On the grappling mat the other guy pretty much had the advantage on me all the way through. He was stronger and had better skills, and got me to tap out after hard matches almost every time. At the SCA practice, one of the better fighters there asked me if I had been training elsewhere because I was fighting very well. He said my shot selection was better, my targeting better, and basically I was fighting better than ever in the 3 or 4 years he has known me.
I can credit that to a few things. First off, I cannot discount that the particular fighters I faced happened to be of sizes, styles, and experience levels that were a good fit for me.
Also, I picked up Miyamoto Musashi's "Book of 5 Rings" for the first time in a long time recently, and after 23 years of armored swordfighting and three years of grappling, I actually started to understand it. Passages about "treading down the enemy" and not thinking to just let him attack and look for an opening made sense in the grappling arena. I then figured out how to apply it to swordfighting.
Grappling takes a lot of endurance, a different kind of endurance from swordfighting. In armor, when you are down to your last ergs of energy, you can focus everything you've got left into one last blow or combination, and if it fails, you can cover up and get out and wait out of range until you are ready to go again. In grappling you don't have that option. If you are tired, your enemy is already all over you and you get gradually worn out until you tap out.
I have seen many, many successful swordfighters that hardly look like athletes, but very few grapplers that aren't extremely fit.
Another key difference between the two sports is that swordfighting can end with one hard percussive shot. Boom. Done. Grappling by its definition is a progression of moves leading to a gradual sinking into a submissive position. But even with the differences in the game, there ares till similar principles and concepts. Aggression, taking the initiative, defending while looking for an opening, and training specific moves all are part of the ingredients of a successful fighter in either game.