According to "Chosun Common Sense Q & A", which was Namseon Choi's 1937 newspaper column, "Subak & Subyuk were the same, a fight game which became a drinking game, children's game. The method is fist, grab moving front & back. Hand & fingers bend." https://pbs.twimg.com/media/Dp0fnPMWwAIfsuM.jpg In 1964, the ethnologist Gimu Hong representing North Korean Science Center Anthropology & Ethnology Research Institute published this book, "there was a game called Subak. This knocks down opponent with punches. Subak was liked by warriors in that era." https://pbs.twimg.com/media/DnvJGLBWwAAauDM.jpg Korean is from Central Asia originally before coming to East Asia, so having boxing is not a surprise. There are also archaeological old Subak pictures representing real life Subak including front-slaps. The following picture is referenced by Chinese Martial Art Encyclopedia page 5 from China (Chinese Martial Art Encyclopedia Editorial Association). https://en.wikipedia.org/wiki/Subak#/media/File:Chinese_Shoubo_(Subak),_Qin_Dynasty_archaeological_picture_on_a_comb.jpg Both players are slapping front cause both players' striking hands are abruptly bent in the middle of their hands to represent fingers curling. Their striking hands are palms with fingers curling in the middle of hands. Even if one of the players was punching, the picture would still be Subak cause Subak had punch according to reputable historians. That picture is widely recognized by scholars to be Subak, representing a real Subak scene 2000 years ago. The decision on the picture is based on the era of picture (the sports existing in that era), motions visible in the sports, etc. China also has a historical data of slapping the top of someone's head so hard to break skull. + Historians say Subak punched. Subak Dance in Manchuria and Taekkyeon also have front-slaps (slapping forehead or chest) and punch. Subak's cousin game Subyuk also has front-slap. (There are historical written description record and photo.) Even if Subak used palm only, Subak players can fight with fists. There are many Korean historical records of fighting with fists in Subak era, including Subak players Gyungseung Du and Euimin Lee punching through wall and punching pillar to shake raft. Also, reputable historians testify that Subak had punch. Subak's name doesn't testify like historians. No matter what Subak's name is, you can't tell whether "clapping" is done front or with fist, or whether there is non-clapping in the game clapping. Subak's name meaning clap proves nothing; historians' testimonies prove rules.