An analysis of all the marathons I've done in the last 10 years.
I’ve done dozens of races and about 15 marathons since I started running. I’ve plotted my pace for 15 official marathons. Its quite obvious now that I’ve plateaued at a nominal pace. You can see that I got fast quite quickly - after about three years I hit my plateau of about 8 minutes per mile.
In my first three years of running I ran about 20 miles a week - sometimes more, sometimes less. I started running fast and a year of intense training about five years in, which got the lowest dot on that graph - a sub 7 minute per mile marathon (which qualified me for the Boston marathon).
I also computed my relative placement in marathons to see how I did compared to others. The relative placement is my place overall divided by the number of people in the race. A relative placement of 1 means that I finished last, and 0.5 means I finished right in the middle.
You can see that over those first three years my relative placement plunged a lot more than my pace. This shows that you can do a lot better in a race by just increasing your pace a little bit. Currently I’m able to hover around the top 15% of any given race.
I think this is a nice illustration of being able to work for something you want. I wanted to become a marathon runner, so I ran. I started out bad (finishing in the last 20% of the my first marathon) but over three years you can see I gradually improved. You can also see that those improvements have lasted over the years, as I continue to run casually.