Specifically, if a certain shoe matches your body in a way that allows you to run with less effort and strain, your brain will let you know it by generating a feeling of comfort.
The difference between comfort and the scientific tools for matching shoes with runners is that comfort is global, whereas the scientific tools are narrow. Foot pronation is only one of dozens of aspects of foot structure, body structure and stride mechanics that determine the shoe characteristics that are best for an individual runner. Feelings of comfort and discomfort account for all of these characteristics. If a particular shoe is right for you in nine ways and wrong in one way, it will feel slightly less comfortable than a shoe that is right in 10 ways and wrong in none. Because comfort accounts for everything, there will never be a scientific tool that surpasses the "feel test."
The Catch to Using Comfort to Select Running Shoes
There is a catch, however. A shoe that feels great when you first lace it up might not feel as good when you start to run in it. And a shoe that feels great when you start to run in it might not feel as good after 6 miles of running. You want the shoe that feels great after 6 (or however many) miles of running and, unfortunately, the only way to find it is through trial and error.
What you're really looking for is not a specific brand and model of shoe—because these are always changing—but rather a specific set of characteristics that you need in a shoe. For example, 30 years of running have taught me that I need a narrow shoe that is light, low to the ground and yet well cushioned—even a but mushy under the heel. I don't always buy the same brand, but I always buy shoes with these characteristics.
If you don't yet know the shoe characteristics you need, step one is to shop not at a "big box" store but rather at a running specialty store with an experienced sales staff. The people who work at these shops have seen everything, so by looking at your foot (factors such as foot width do matter) and asking you a few questions, they will be able to zero in on a few models that are most likely to feel very comfortable for you to run in.
Step two is to try on as many different shoes as the person helping you has patience for. The more shoes you try on, the better your chances are of finding a very comfortable shoe. Be sure to do a little running in each shoe that feels great when you first put it on. Purchase the pair that feels best of all to run in.
Step three is to get out and train in your new shoes. Understand that this is an experiment and there's no guarantee a shoe that felt super comfortable in the store will still feel great at the end of a 40-mile week. If it doesn't work out, try again. Once you find a shoe that really does work, itemize its key characteristics and look for these in any shoe you purchase in the future.race.