In the series The Flash on CW, at the beginning of each episode's intro Barry Allen says "I'm the fastest man alive". But in each season, there was a much faster character in the show than Barry. Like Zoom, Savitar and even the Kid Flash.
Why are those other characters (mainly villains) faster than Barry? and How?
When there are other people faster than The Flash, then why is Barry called the Fastest Man Alive in that show?