The four seam fastball is widely regarded as the main key to advancing to the next level of play. One of a baseball scout's main criteria when scouting a prospect is how fast he throws a four seam fastball. The game of baseball keeps on progressing, and as research on the physics of throwing is published and recognized, fastball velocity training has become more effective. This can be shown by looking at the average fastball velocity in the major leagues as time progresses. In 2008 the average fastball thrown in the MLB was 90.9 mph. 5 years later it had risen to 92.0. To show the effect that this increase in velocity has had on hitters in the big leagues, we can look at the runs scored stat. In 2008, the average number of runs a team scored a game was 4.6; 5 years later as the velocity increased, the average dropped by half a run a game, to 4.0.