It's abbrevation of "YaDag BoLTsiN" by collecting uppercase letters and it's in Mongolian language.
Writing it in Mongolian (Яадаг болцын).
If it is translated to English, It means:
"Who cares, I can do it too",
" who gives shit"
"i could give damn"
"I don't care, who the fuck are u"
1) those guys are really good at sport. DGBLTsn