When I was a kid, the adult science writer I read the most was Isaac Asimov. He wasn't the most expert in any of the fields he wrote about (except, perhaps, biochemistry, which was his Ph.D.), but he was easy to read and understand.
Some call that kind of writing "accessible," which, I guess, means that you don't need a lot of background to follow what the author is saying. But I don't think that really captures it. It's been a while since I read any Asimov, but I bet that even in subjects where I have a fair bit of background -- math, say -- Asimov would still be a cleaner read than other authors. I think Asimov's real skill is: he's just really, really good at explaining things. In fact, he's been nicknamed "The Great Explainer."
Explaining is one of those important skills that, in my view, gets no respect at all. Ask what makes a good teacher, and what do people say? Motivating the students, and understanding every pupil's strengths and weaknesses, and being able to gauge the mood of the classroom, and being an interesting and varied speaker, and using multimedia and experiments, and knowing the subject, and stuff like that. But to me, the biggest thing is: finding explanations that students will actually understand.
In my life, there have been things that confused me for years, or that I understood but didn't "really" understand. Then, one day, either I figured it out for myself, or I read something that instantly ended my confusion. And I asked myself, "Why the hell didn't anyone explain it properly before?"
For example ... for years, I was confused about how one of the aspects of regression analysis. Statisticians would say, "IQ accounts for 35 percent of the variance of salary, and parental income accounts for another 40 percent." I wondered, how doe that work? What if the effect of education tuns out to be as important as IQ? Then, you have 110 percent! What's going on?
But I just lived with it, until eventually I figured it out. What's the explanation? It's a law of nature that standard deviations are pythgorean. So you can never find independent factor "triangle sides" whose squares add up to more than 100% of the overall "hypotenuse".
And with that, it made sense. Even though I knew the sum-of-squares thing in another context, I never made the connection, and it was never explained to me -- until I figured it out, two decades after my last statistics class.
OK, was that one too mathy? Here's an easier one: why it takes 10 runs in baseball to create one additional win. I knew it was right, but I understood why only in a roundabout kind of way. My gut still had a vague notion that 10 runs was much too high, and I had to keep correcting my gut.
But then I found an explanation where it really made sense to me. If you prefer a shorter summary, here's Eric T. with the hockey version (6 goals = 1 win):
"... imagine taking an average team, picking six of its games at random, and giving the team an extra goal in each game.
"Three of those games will be games it won anyway, so your extra goal doesn't change the result. In another game or two, the team lost by two or more and your goal still doesn't help. Only occasionally do you turn a loss into a win (or overtime loss), and so in the end, your six extra goals only produce roughly two extra points."
It's not just me, right? "Why didn't anyone explain it that way before?" happens to everyone.
Think about something you understand well, but had a bit of trouble with in the beginning. Don't you think that you could have learned it in half the time if it had been explained differently? How much time is wasted struggling through murky explanations in pedantic textbooks, or incoherent notes from class, when you might have been able to understand it in five minutes if it had been done a bit better?
There are many reasons I admire Bill James. One of the biggest is his ability to explain the things he's discovered. His explanations are ... well, I think they're nearly perfect. He explains what happens, and why, and how his method works, and it all comes together so well that you can read it once, at normal human reading speed, and ... you just get it. His explanations just penetrate your brain effortlessly.
A lot of that is that he's such a good writer, but that's not enough. William Shakespeare was a good writer, but I wouldn't bet on him being able to explain Runs Created. A good writer will say things well, but a good explainer will also choose the right things to say.
I used to teach regularly, a class in how to use a certain niche software product. There's no proper textbook, so I had to figure out how to explain it so that the students would actually get it. Some things I did worked better than others, and I'd try adjusting what I did from class to class. Occasionally, I would think, "Geez, you know, it's a complicated subject ... this is probably as clear as it can be explained, and they're going to have to work a bit to actually get it."
But then, I would stop and think, "What would Bill James do?" And I would realize that if it were Bill, he would have a way to get the point across. He would have found the right analogy, or the right story, or the right thread of logic.
I've learned a lot of things, beyond just baseball, from following Bill's work over the last thirty years. One of the most important is: nothing is so complicated that it can't be explained well. If I try to explain something, and it's not working, and people are having to work hard at understanding ... I have to think: it's my fault. My explanation isn't good enough.