In 1950 H&B began putting "REG. U.S. PAT. OFF" underneath the center oval. This replaced the "TRADE MARK REG." which had been there previously. Please notice that the wording begins under the O in Louisville and ends under the letter K in KY. Also, notice that the & in "H&B" in located under and between the 1 and 2 in "125".

In 1961 the type set changed in the wording "REG U.S. PAT. OFF." and is now a smaller font. Also, notice that the & in "H&B" is directly below the 2 in "125"

In 1965 the entire "REG. U.S. PAT. OFF." is dropped and replaced with the (R) Registered Trademark is placed after Louisville Slugger in eh center oval.

The change in 1969 is very subtle. The labeling is the same as the 1965-68 era except for the P in the word Powerized just above the center oval. Notice that the P in Powerized is flush in the 1965-68 era where as the bottom loop of the P now cross over.

In 1973 a (R) Registered Trademark is place above the d in Powerized just above the center oval.

In 1976 H&B began placing the model number on the barrel next to the word genuine. In addition, in 1976 a Liberty Bell stamp replaces the word Powerized for just one year to commemorate the Bicentennial

In 1977 the Liberty Bell is dropped and the model number remains on the barrel. Note that the Powerized is back on and the model number remains on the barrel

1980 marks a significant change in labeling for H&B. The center oval stamping is completely changed to read LOUISVILLE SLUGGER. The oval is rather large measure about 4.5" across.

In approximately 1983 (note there is some overlap during that year) the center oval is made smaller to only measure 3.5" across. Subsequently the 125 also shrinks significantly. Also note that sometime in 1985 and running into part of 1986 player signatures are foils stamped on eh barrel rather then burned.

In 1986 a (R) Registered Trademarks is placed after the LOUISVILLE SLUGGER under the players name on the barrel

In 1990 the LOUISVILLE SLUGGER under the player's name is dropped completely.

Beginning in 1991 team names are burned under the player's names were Louisville Slugger was previous to 1990

In 1998 the font or type set for of LOUISVILLE SLUGGER in the center oval changes and becomes shorter and wider. The difference is subtle.

Beginning in 1999 the MLB logo is stamped on the barrel. Please note that some players requested that this be removed during this time (i.e. A ROD).