late 90's on several high level Navy base teams, and in those games, no 5 man, no pitcher masks, but the bats back then were dead when compared to today's Sure pitchers were hit and the batter apologized but in the several tournaments I never seen a pitcher knocked out by a ball.
Mid 2000's to Early 2010's - this is the shaved bat era to be honest. Repaints, shaved.... etc... composite just came out but was not dialed in so players would gut them to get more spring on the ball contact.. People accusing everyone of hitting glass and most of the time it was true. Middle hitting was about the same, but when a player got hit with a known shaved bat, it was on and the Middle War commenced. I have seen many of these. If your teammate is blasted intentionally, its fair game in my opinion and fire away until the umps do something.
Worst shave bat experience is watching a church team in Oklahoma with an average age of 52 hitting one bat the whole game and it showed like a shotgun. 67 year old pastor blasting 300+ missiles into the light tower in LC... Seriously, there was one bat in the dugout, everyone hit it... Some people walked over to pay 300 bucks for it too..
Today, there is zero reason to shave a bat...... period..... Bats now days are bazookas out of the wrapper...
I dont play conference, but those dudes do not need shaved bats and I am sure no Major or List player hits glass.... if there is shaving, its because the conference lets C teams in and they feel they need an advantage...