Apparently the ignorance on this board goes way beyond just running. Since its inception, mixed martial arts has taught us that one dimensional striking disciplines such as boxing, karate, and taekwondo are very unsuccessful outside of there own competitions. In the early days, grapplers absolutely dominated the sports and that is still true today. Of the seven weight classes in the UFC, five of the titles are held by fighters with a wrestling base. The other two are high-level BJJ black belts and often use their grappling to keep the fight on their feet.
Onto Mike Tyson, sure a phenominal athlete in his day, but don't just assume that he's the most dangerous/powerful striker to have ever lived. Several K-1 level strikers like Badr Hari, Sammy Schlet, and Alistair Overeem are powerful guys and they use more than just their fists. If they stayed on the outside and batter a boxer with legs kicks and hopped into the clinch and delivered some vicious knees, the fight would be over. If, however, they were forced to punch only, it would be a quick night.
It's ridiculous to assume that just because an athlete is dominant in one sport, they would dominate in all others. Because in truth, boxing, mma, and kickboxing are all completely different sports and require different skill sets. Sure many of the skills are transferable, but the timing and rules predicate much different approaches especially between MMA and boxing. Take any well rounded mma fighter and he will beat the best boxer 9 out of 10 times. Of course the boxer will always have a punchers chance, but there's always the chance that Bekele will miscount the laps on the track, while Alistair Cragg will actually finish and win the race. Does that make Cragg a better runner?