Almost everyone! That is the great thing about this art. It was adapted from Judo for the purpose of increasing combat effectiveness without as much reliance upon strength and athleticism. Of course, those factors will always matter, all things being equal. However, technique is a great equalizer and something that any dedicated practitioner can improve upon, ultimately making themselves much safer in a self defense situation and much more effective at the art in a more casual training situation. Professor Ryan, for example, is 5’5″ and 150lbs, yet is almost completely un-intimidated by the size of others because he routinely demonstrates superior technique routinely submitting bigger, stronger opponents. For a more popular example in modern jiu-jitsu culture, see Marcelo Garcia. For a more realistic combat oriented example, watch Royce Gracie in the early days of UFC before weight classes, rounds, and most of the existing rules. You can also see many examples of female grapplers submitting male opponents on YouTube, and we encourage you to search for those.