You might think of stone skipping (or “stone skimming,” as some weirdos like to call it) as a perfectly fine leisure activity with only casually competitive elements. You would be wrong.

In fact, there’s a whole world out there of professional stone skimmers, who compete to see who can either skip a stone the furthest distance or the highest number of times in one go.

According to the BBC, the rules for the world stone-skimming championships state that stones must come from naturally occurring island slate. However, during the competition, some people realized that a few competitors were using stones that were suspiciously circular — and so, they publicly accused the competitors of cheating.

Turns out, the accusers were correct, and those who used the ground stones admitted to their rule violation.

It just goes to show that, if a sport exists, people will find a way to cheat (and gamble) on it.