Due to the fact that the quality of performances are so high at the Olympic Games, the margin for error is so small.
World records are set by shaving off a tenth of a second here or half of a second there. Athletes have prepared so rigorously for the events that progress is made by the slight improvements during their performances and tapering their training so they peak at the right time.
This all went out the window for Russian diver Nadezhda Bazhina yesterday.
The 28-year-old is a hugely experienced diver, having won 14 medals at European Championship level - six of which are gold.
This effort though in the 3m springboard is one she will want to forget pretty quickly. It was supposed to be a three-and-a-half somersault, but the result was something unrecognisable.
You have to feel for her, but she can take solace in the fact that she isn't the first to suffer such a setback.
The aptly named Stephan Feck also was left redfaced after this effort in London four years ago.
