The Physics

                      
 

Physics has a lot to do with how long it takes for a runner to get to first base.  There are several forces involved, such as the force of friction, air resistance, normal force, the force of gravity, the mass of the runner and his center of mass.  All of these forces combined make a huge difference in how fast the runner arrives safe on first base after a very close play.  One of the arguments from the supporters of the first theory is that the force of friction applied by the ground when diving headfirst is much much bigger than the friction on the baserunners feet which make you slow down as opposed to maintaining a constant velocity.  Also, diving is not as consistent as running straight through.  Sometimes, the runner could dive too soon increasing the force of friction which can make it more dificult for him to reach first base and cover those last few centimeters. 



        The next page shows a video by sports science on ESPN in which they discuss in detail both of the theories.