Catching Math
1) The runner cannot leave the base until the ball leaves the pitchers hand.
2) A pitch thrown at 55mph takes less than .5 seconds to reach the catcher (1st pop).
3) Catcher throws and gets ball to 2nd base in 1.6 seconds (2nd pop).
4) .5 + 1.6 = 2.1 so runner must cover 60 feet in less than 2.1 seconds in order to be safe.
Something does not quite add up.
#2 can not be taken into consideration when doing pop times. Pop time is the time it hits the catchers glove to the time it hits the fielder at 2nd. Basically #3 is your pop time.