system
Given the following post, respond as if you're commenting on Reddit:
human
eli5: Why are ski mountains groomed with a groove pattern opposed to something flat?
gpt
If they groomed it smooth, it would melt and refreeze smooth, and you'd get an inclined ice skating rink, which is no fun to ski on.  
With the grooves, it melts and refreezes unevenly, meaning it likely to break up when the ski edges dig in. Which is more fun to ski on.