Medical Definition of Z LINE. : any of the dark bands across a striated muscle fiber that mark the junction of actin filaments in adjacent sarcomeres.Britannica.com: Encyclopedia article about Z line.efinition of Z LINE. : any of the dark thin bands across a striated muscle fiber that mark the junction of actin filaments in adjacent sarcomeres. ADVERTISEMENT.
The average fb speed in the MLB is 91-92ish. Catchers compete with this when trying to throw down a runner at 90ish. The average throw speed from third base is 80 MPH. As for the rest of the positions I am not sure of the exact average, but it is not as fast or faster than pitch speed.
The pitch is used often by the pitcher to get ahead in the count or when he needs to throw a strike. This type of fastball is intended to have minimal lateral movement, relying more on its velocity. It is often perceived as the fastest pitch a pitcher throws, with recorded top speeds above 100 mph. The fastest pitch recognized by MLB was on September 25, 2010, at Petco Park in San Diego by then Cincinnati Reds left-handed relief pitcher Aroldis Chapman. It was clocked at 105.1 miles per hour. April 19, 2011 Chapman lit up the stadium radar gun at 106 MPH (the TV-reading had his pitch at 105 MPH, and the pitchF/X reading was actually 102.4 MPH).