The Gainer in tricking can be quite confusing. You may have heard names like gainer flash, cheat gainer, slant gainer, kick the moon, moonkick and maybe even a few more. And then the same trick is being called different by many people. That’s because the gainer is part of many sports and thus it’s always different depending on who you ask.
In most sports it’s a backflip that travels forward. So a backflip that is “gaining” distance. The way you take off doesn’t matter. You can take off two-footed or swing into it with one leg. As long as it’s a backflip that is traveling forwards, it’s a gainer. And then there is the gainer in tricking…
In tricking it’s simply a backflip that takes off of one foot. However a gainer doesn’t have to be completely inverted to be considered as one. You can flip off-axis to the side instead of completely backwards and it would still be called a gainer in tricking.
The base variation of this trick is usually not tucked but similar to a flashkick where you keep the first leg straight through until the landing (that is where the name “gainer flash” came from). Tucking your legs in for a gainer is not very common in tricking and usually more seen in parkour and freerunning. In tricking you could simply call that “gainer tuck”.
Then there is also the very confusing name “cheat gainer”. The name has its origin in the parkour community and was originally used to describe a gainer that is “cheated” over to the side instead of a true backflip. Hence the name “cheat” gainer. In tricking however “cheat” is a takeoff-technique commonly used for cheat kicks and raiz-type tricks. That’s how the name “slanted gainer” was born, to avoid confusion. But as you see it just made everything even more bloated and confusing. A cheat gainer is still just a gainer. It’s just not as inverted.
Gainers are also sometimes called “moonkick” or “kick the moon”. In tricking a moonkick is a gainer that terminates in a hook or outside crescent kick. If there is no kick, it’s not a moonkick. The true technical term for the moonkick would be “gainer hyperhook”.
As you see the term “gainer” can be very confusing. When Veli-Mati “Vellu” Sarella landed the world's first double gainer on flat ground many people didn’t count it as a double gainer, because it was “just” a one-footed double backflip. However in tricking that is exactly what a gainer is:
A backflip off one foot.