Clustering is an unsupervised learning method where data points are grouped together based on similarity, without being given labels beforehand. It’s like looking at a group of runners without calling them “beginners” or “advanced” first, you just observe their performance metrics, and the patterns naturally form groups.

For example, when I pace different athletes, I notice clusters: some have steady heart rates even at slower paces, others can handle speed but fatigue earlier, and another group balances both. These clusters emerge not because I pre-labeled them, but because their bodies and performances show similarities. In the same way, a clustering algorithm takes raw data, whether from running paces, heart rates, or even movie preferences, and organizes it into meaningful groups.
You must understand that there is more than one path to the top of the mountain.
Miyamoto Musashi, The Book of Five Rings
The insight is powerful because it highlights patterns you may not have expected, allowing more personalized coaching and smarter decisions.
