All about baseball decals and stickers for your sports In fact, players have not worn helmets at all for most of baseball history, or at least not helmets that we are aware of today. It was not until 1971 that players had to wear helmets on their way up to the helmet sticker, according to sources. https://baseballracks.blogspot.com/2020/10/all-about-baseball-decals-and-stickers.html