The thing about running the same race, year after year, is that it provides an objective marker by which to judge progress. There are variables, of course, beyond baseline fitness. But in general, it's the best we can do. And since I'm getting up there in my trail running years now - I'm only half joking - I've now got a race for which I can call up four results.
2012: Didn't run it
This is not remarkable progress, of course. No massive jump, hinting at a deep well of untapped abilities. But it does speak to how one can shave time, and eventually, the resulting cut seems pretty significant. I also think it's interesting that my biggest improvement came four years after my first running. Which could, if I'm being optimistic, suggest that I still have some progressing to do, and that I haven't quite leveled off. I turn 27 in two months, so I wouldn't expect physical abilities to deteriorate soon. That will happen, of course. Inevitably. And then regression will follow. But for now, I'll indulge myself with the fantasy of perpetual linear progress.