Why do MLB players wear helmets with only one ear flap? - Quora
Batting helmet - Wikipedia
In baseball, why have there never been any players who have worn a mask or helmet while playing the game (like hockey)? - Quora
C-Flap helmets may look weird, but MLB stars are picking safety over aesthetics - The Washington Post
Do any MLB players still play without batting helmets? - Quora
Will pitchers ever have to wear helmets? - Quora
Why do MLB players have pine tar on their helmets? - Quora
Does Major League Baseball (MLB) have to approve the font used for names on hats or uniforms? - Quora
Why are MLB players wearing 21 on their sleeve? - Quora
Uni Watch - History of headgear in MLB Alex Torres - ESPN
Who decides what hat baseball players wear when they retire? - Quora
Why do MLB players wear helmets with only one ear flap? - Quora