Baseball agent Joshua Kusnick had a video of Taylor Grover throwing 100 miles per hour in Double A and wanted to maximize exposure for his client, who had reached 102 this past season in independent ball. Kusnick mentioned Grover to The Athletic’s star writer, Ken Rosenthal, who in turn directed the agent to the @PitchingNinja.
That is the Twitter handle of Rob Friedman, an executive with a suburban Atlanta software company who is also a self-taught pitching coach. His @PitchingNinja account has attracted more than 100,000 followers—including many big league pitchers—as a repository of pitching GIFs and videos.