Each dot = one labeled training row plotted on two of the 22 features. Patterns to look for:
- Clean separation: green clusters on one side, red on the other โ these two features alone predict outcome well
- No separation: dots mixed โ these features aren't useful together (model has to rely on other dimensions)
- Edge cluster: corner of the plot is all one color โ strong rule (e.g., "high RVOL + low IV = always wins")