Chances of success
It is inevitably a challenge to run a marathon, and not all succeed. I’ve spent some time trying to figure out what my odds are. I think its important to be realistic; you’ll spend an awful lot of time running and its not without risk. (Injuries)
I’ve read that good predictions come from a) looking at prevalence, and b) update your estimates as more information becomes available. So, that’s what I’ll do.
Prevalence
My initial thought for prevalence was to get numbers for a bunch of marathons, correlate the finish rate with elevation and arrive at a number. But these stats were not readily available, so I skipped that.
Instead I looked at the finish rate for the actual race. Fewer data points, but perhaps more accurate.
These were the numbers for last two years.1 (DNF: Did Not Finish, DNS: Did Not Start)
| Year | Finishers | DNFs | DNSs | Rate |
|---|---|---|---|---|
| 2023 | 69 | 8 | 20 | 71% |
| 2022 | 44 | 2 | 15 | 72% |
So, the prevalence is around 70%.
Initial conditions
Based on the prevalence, I can make some adjustments based on my current state.
- General dropout before actually registering (-10%)
- I assume a percentage of those that decide to run realize they won’t, before registering.
- Fitness compared to failed runs in prevalence2 (+0%)
- General life circumstances (-15%)
- I got kids
- There is a vacation period where I will struggle to get time to run
- I’m prone to procrastination and setting too ambitious goals
- Injuries (-5%)
- I have a slight feeling in my knees. Currently not limiting, but a worrying factor.
In total, this means a reduction of -30%.
Continued evaluation
These factors will be evaluated every four weeks, to see if I’m increasing or decreasing my odds of finishing.
- Adherence to training schedule
- General fitness feeling
There is a last category of factors that affects the odds, and that are factors that are specific to the day you run. I’ve only managed to come up with weather as a race day factor, but there might be more.
Summary
I peg my chances to 40%, based on prevalence and individual factors. Its maybe not a morale boost, but I think its realistic. I hope the chances will rise with continued evaluation, or I might struggle with motivation. For now, its sufficient, as I haven’t deviated much from my normal exercise amount.