@article{oai:geitan.repo.nii.ac.jp:00001523,
 author = {洲, 雅明 and 榎本, 至 and 南, 隆尚 and Suga, Masaaki and Enomoto, Itaru and Minami, Takahisa},
 journal = {大分県立芸術文化短期大学研究紀要},
 month = {Mar},
 note = {The purpose of this study was to clarify the usefulness of the extra-man offense pattern, and its effectiveness at breaking the defense formations in water polo games. Related data were obtained and analyzed from the following games: (1) 89 extra-man formations used in four final games of the London Olympic Games 2012 (LO), (2) 64 extra-man formations used in all eight games of the Japanese 2015 championships (JC), and (3) 55 extra-man formations used in the final eight games of the Inter-High (IH) School 2014 championships in Chiba.
The number of extra-man offense patterns across the games were 11.1±2.7, shots during extra-man offense patterns were 4.0±2.8, and goals in extra-man offense patterns were 3.4±2.6 in LO, and this was significantly higher (with p < 0.001) than that for JC (4.0±2.8, 3.7±2.7, 1.5±1.7) and IH (3.4±2.6 , 3.1±2.5, 1.0±1.0) respectively. 
Offense players tried to break defense formations by faking and moving during pass transitions in order to shoot accurately and score in extra-man offense formations. Breaking defense by offense was observed in 28 of the LO (36%), 28 of the JC (38%) and 16 of the IH (33%) instances. There was no difference in the ratio of breaking defense formation between JC and IH in comparison with the LO. However, the ratio of shots in extra-man offenses was low due to poor pass and shot techniques in JC and IH. Therefore, it is suggested that the JC and IH are effective at breaking defenses.},
 pages = {25--32},
 title = {水球競技における退水時攻撃のディフェンスの崩しについて －五輪、日本選手権、高校総体の比較－},
 volume = {53},
 year = {2016},
 yomi = {スガ, マサアキ and エノモト, イタル and ミナミ, タカヒサ}
}