Have you ever noticed how some hitter’s helmets have one ear flap and some have two? Have you also noticed how players always have an ear flap facing towards the pitcher? That is no coincidence and is a helmet safety feature combined with comfort options for batters.
If a player only bats left-handed, his helmet will have an ear flap only covering his right ear. He will never have his left ear exposed to the pitcher and therefore does not need the extra ear piece. This is a comfort and style option used by players at the Major League level.
The same is true if a player only hits right-handed. He will only have an ear flap covering his left ear. If a player is a switch hitter, he will have two ear flaps as he will have either of his ears exposed to the pitcher depending on which side of the plate he is hitting from. This way a player only needs one helmet no matter if he is a lefty, a righty, or a switch hitter.
Only Major League players and those in the minors typically have helmets with only one flap. College, high school, and below are typically required to have two flaps on every helmet no matter what for safety issues.
It is a little strange that MLB would not implement a rule requiring all batters to wear double flapped helmets. Just because a hitter only uses one side of the plate does not mean that he has no chance of getting hit in the exposed part of his head with a ball. A player running the bases who only has a left ear piece could be hit on the right ear by a throw from an outfielder. This rarely happens, but there are many rules that are in place for incidents that rarely occur.
All players have worn helmets with two flaps all the way up until the professional level. It wouldn’t be a radical change, but one that would be justified based on the fact that every other helmet has two flaps. It is a safety precaution that is not necessarily needed but seems right up the alley of MLB officials to consider and soon enforce.