Rules are the reason why most sports maintain some sense of decency and decorum. Without rules, all sports—from football to pickleball—would descend into anarchy.
How do I know? Rules may stop most people from committing crimes, but they also inspire the highest levels of mischief.
The existence of rules prompts athletes and coaches to turn those same rules into a bureaucratic stranglehold on their opponents—or worse, a bludgeon by which the minutiae of a particular rule is exploited mercilessly.
The "cheap shot" operates within a gray area that keeps one foot in the world of rules and the other in the world of anarchy. Sometimes a cheap shot is blatantly illegal, but the reason it's call "cheap" is because nothing can really stop it and often the official judgment can't be rendered in real time.
Cheap shots infuriate because they reveal the fragility of the rules.
Worse still? Far too often, the benefits outweigh the risks; a multi-game suspension or fine is a fair price for knocking a great player out of a game or series.
While not all cheap shots are legitimate attempts to injure another person, plenty have shown that if you want to make your opponent suffer, all it takes is a split second of chaos.
These are the most painful cheap shots in sports.