On average, a professional rugby union player is more likely than not to sustain a concussion after 25 matches
James Rafferty, Craig Ranson, Giles Oatley, Mohamed Mostafa, Prabhat Mathema, Tom Crick, Isabel S Moore
British Journal of Sports Medicine Aug 2019, 53 (15) 969-973; DOI: 10.1136/bjsports-2017-098417