Downright Filthy Pitching Book 1 introduces you to the world of Effective Velocity. Book 1 introduces you to the science behind what causes hard hit balls to happen and……..how to avoid them. 90% of all hard hit balls are explained by Effective Velocity concepts. Ev Tunnels, as described on MLB Network shows, is an Ev concept that was discovered at a time when MLB pitching coaches thought deception was something pitchers just ‘had it’ or not. There are many more elements discussed in this 1st of a 4 book series.