Nellie Kim (SOV)
Shigeru Kasamatsu (JPN)
Buckle up, because we’ve got a lot to get through with this little vault and its naming. First, this is one of the myriad skills Nellie Kim has gone back and named after herself in the code of points over the years, but this one is especially rich because Nellie Kim and Natalia Shaposhnikova both successfully landed this vault at the 1978 world championships. In the code of points, however, it is named after Kim only, and Natalia Shaposhnikova is nowhere to be found. Also nowhere to be found are the generations of gymnasts (until this very quad) who co-founded a skill at the same competition as another gymnast doing the same skill and got it named after neither of them. The rules are different for Nellie.
Also, the number of people who call this vault “The Kim” is zero.
Now to the issue of “Tsuk full” versus “Kasamatsu.” For the purposes of the women’s code of points, these are the same vault—the same entry, the same amount of twisting—and if you’d like to just leave it there, you are permitted to do so. The precise technical difference between the two vaults, however, concerns the direction of twisting. In a Kasamatsu, your left-handed round-off onto the table continues twisting to the left. In a Tsukahara full, your left-handed round-off onto the table becomes twisting to the right.
This is important in the men’s code, where a Tsuk full and a Kasamatsu are specifically different vaults. In the women’s code, the two are not differentiated, so the difference is not significant. Because pretty much everyone these days performs the vault with the Kasamatsu technique, the two terms are used interchangeably in women’s gymnastics, but remember that Kasamatsu refers to a Tsukahara with a full twist. So then a Kas full would be the same as a Tsukahara double full.