get their hand above the rim? I find it hard to believe 12'6" is the NBA record. There are pictures/video of Michael Jordan and Lebron James dunking with their heads above the rim.
Sport Science: Dwight Howard Max Vert Reach
https://www.youtube.com/watch?v=w8Wiq-POmFA
Doug Thomas 13' off one leg who played for Iowa and was in the NBA D league
https://www.youtube.com/watch?v=Dr1-c8kg0DE
Volleyball player Matey Kaziyski 390cm (12' 9.5") high reach attack
https://www.youtube.com/watch?v=BvoGpl4rW5A
Leonel Marshall Volleyball almost 12' 7" with a 50" vert
https://www.youtube.com/watch?v=n8Q0KiwNYN8Edited by Tiger_1995 at 15:39:27 on 02/14/18