The data

This app is built on split times from 2,500+ runners who raced the Superior 100 between 2014 and 2025 (every year except 2020). For each runner, we have the time they came through all 14 aid stations, from Split Rock at mile 8.4 all the way to the finish at mile 102.

Finding comparable runners

When you tell us where and when you last saw your runner, we search through all 2,500+ historical runners to find people who were at that same checkpoint around that same time. These are runners who were moving at a similar pace, in a similar position in the race.

Runners who match closely get weighted more heavily. Someone who was at Finland at exactly 10 PM counts for more than someone who came through at 9 or 11.

The prediction

Once we've found your runner's comparable group, we look at when those same runners reached each upcoming checkpoint. If they mostly came through Sonju between midnight and 2 AM, that's your window.

The median is the middle of that group — half arrived before, half after. That's your best single estimate.

What the shaded bands mean

The chart shows two shaded regions:

The bands get wider further into the race because runners spread out over time. Some people stop longer at aid stations, some hit a rough patch, some have a great day.

Multiple sightings

Each sighting narrows the pool. A runner seen at Silver Bay at noon and Finland at 10 PM is a much more specific profile than either observation alone. We find historical runners who match both.

In practice, two sightings can cut the prediction window nearly in half, because you're filtering out runners who happened to match one checkpoint but ran a completely different overall pace.

Important caveats

Tips for spectators

Start Predicting →