My design process is often largely intuitive rather than analytical. So, for example, while I will certainly take a look at casualty returns when designing a game on an ACW battle, I'm not going to plug those returns into some kind of algorithm, or determine the average losses per battle per brigade over the course of a campaign in order to determine the fighting value of the unit, or the leadership ability of its general.
Rather, I make these decisions with my gut, with what "feels" right. Then I try it out and see if it works. If it doesn't, I adjust, then I try again. And so the process is not only more intuitive, but also more iterative. It also makes it harder to discuss the process sometimes. If people ask me, "Why is this that way, and that this way?", I usually can't answer beyond saying that it felt right, or that I tried it some other way and it didn't feel right.
This is invariably disappointing to a certain type of wargamer, especially the sort who plays the games not so much to enjoy themselves or to engage with the history, but to express their intellectual superiority to the designer. To them, assigning this unit a combat factor of 3 and that unit a combat factor of 4 must be based on some kind of rigorous mathematical formulae, and the idea that a designer might in any way "wing it" is yet another testament to the way in which the hobby has deteriorated since 1974.
That doesn't mean, of course, that the designer - any designer - including and especially this designer - is infallible. When you make decisions with your gut, sometimes your gut is wrong. Sometimes what feels right, in retrospect, starts to feel wrong.
For example, in my very first wargame, Blood on the Alma, I had to determine how to express the firing ranges of Minié rifles and artillery, in hexes. Both worked out to be a little over two hexes at my chosen scale. Because the Minié outranged the artillery - and because this was a vital part of why the battle happened the way it did - I decided to round the artillery down to two hexes and the rifles up to three. This gave the rifles a range that was, strictly speaking, ahistorical. But in broad strokes it captured the essential nature of the Russian dilemma - that they could be fired upon with impunity - and it enabled the game to be played on a very compact eleven by seventeen inch map. Which is what the publisher required. So, for me, it felt right at the time. Some gamers however were very literal about it, and found the whole three-hex Minié range thing quite disturbing.
Now? Looking at the design, it's apparent that I should have used a different and more granular hex scale, or applied some other form of abstraction to model the superiority of the Minié as a long-range weapon. And indeed, in adapting the game to function within the ruleset for the Shot & Shell Battle Series, under the new title The Heights of Alma, the game does indeed use a very different hex scale, being played on a twenty-two by thirty-four incher.
But again, even when redeveloping my very first game, and applying the craft that I've learned after working on more than two dozen wargames, my process is still largely intuitive - I'm still making gut decisions. I'm still trying things to see if they work, and then trying something else when they don't. I'm still largely dependent on my own judgment, my own sense of whether or not the thing feels right. I will say however that the ability to make that kind of judgment call is a bit more finely tuned, but it's nothing I can quantify.
And if all that sounds rather ad hoc and haphazard, well, sure, it is. And I honestly used to worry about that, especially when I'd read notes by this designer on how they calculated movement allowances, or that designer about how they collated data about how Stonewall Jackson's blood sugar impacted his performance. And here I was, rating this leader at three stars and that one at two because after doing my research, I simply felt that one was better than the other. It gave me a serious and classic case of imposter syndrome: sooner or later, everyone would realize that I had no idea what I was doing.
There were a couple of things that helped me get over this. Probably the most important was the same thing that usually helps someone get over this sort of thing: I kept doing it, and kept doing it, and did it some more, and eventually realized that since I was doing it, I could do it.
Beyond that though was the realization that a more detailed model isn't necessarily a better or more accurate one - and that, in fact, it's usually worse, because it captures the details without capturing the essence of the thing. The statistician George Box famously wrote that
Since all models are wrong the scientist cannot obtain a "correct" one by excessive elaboration. On the contrary following William of Occam he should seek an economical description of natural phenomena. Just as the ability to devise simple but evocative models is the signature of the great scientist so overelaboration and overparameterization is often the mark of mediocrity.
Reading that definitely made me feel a lot better about trusting my gut. It also prevented me from getting too far in the weeds and trying to cram too many details into the design. I listened to an interview with the designer Ted Racier not too long ago, where he said something that I found really interesting. I'm paraphrasing from memory, but the gist of it was that he only researched to the point where it was useful; once he got what he needed, he stopped digging. And that is, to a degree, how my own research works; once I've soaked in the topic a bit, and have a general understanding of it, I then only dig in as much as I need to inform my decisions.