Where Do You Touch a Base?

When rounding the bases, which part of the bag do you tag?
Just about every baseball player would answer with "the inside corner."  And they would be correct.  However, when you go farther and ask "what part of the inside corner do you touch?" the answers probably don't come so quickly. 
It would be nice to just be able to fly around the bases and let your speed make up for  any mechanical errors of running the bases.  Unfortunately, most players (I was included in this group), need to pay attention to the many little things associated with base running to get the most out of whatever speed they possess.  
One such little thing is where a runner touches the corner of the base.  The photo above shows two numbers on first base.  Number 1 is placed on the side of the base that faces home plate.  Number 2 is placed on the side of the base that faces second base.  
When many players round first base they will touch the inside corner of first base where #1 is located.   When done this way, normally the heel is near or on the dirt and the front half of the foot is higher up the bag.  When a runner hits the #2 area or more of the second base side of the corner, his heel is up on the bag and the front part of the foot is lower.  This enables the runner to land and push off in the direction of second base.  Hitting the bag more in the #1 area will actually slow the runner down a fraction.  Think of running across a street and then stepping on the front edge of the curb.  The impact is going to slow you down.  As a runner, you obviously want to continue building speed around a base and not do anything that will slow you down.  Touching the #2 area will allow you to do that.
It may seem trivial and may not slow you down much, but us running mortals need all the help we can get!