Baseball Bat Reference - BatReference.com

In 2002, Louisville Slugger introduces a new era in bat labeling known as the "TPX/MLB logo." The Major League Baseball logo is dropped from the center of the two labels, and a new logo is placed exactly opposite the location of the barrel label. The logo consists of a TPX logo next to the Major League Baseball logo outlined. Also, in 2004 Louisville Slugger begins using laser engraved barrel labeling at times. The first appearance of these bats was late 2004. As well, Louisville Slugger introduces M9 bats made of maple wood. These bats lack an engraved Louisville Slugger centerbrand and have a sticker logo instead. Also, some AirDried bats begin to surface in this era(seen instead of Powerized next to the centerbrand).

This particular label period is known for being the first to see the Major League Baseball logo appear on pro model game used bats. In 1999, Louisville Slugger added a MLB logo right between the centerbrand and the barrel label known as the "sweet spot" of the bat. Some players, including Alex Rodriguez and Ken Griffey Jr., eventually requested that the logo be removed on their bats. Rumor has it that this was because the best autograph location was being taken away by the MLB logo. In 1999, the logo appears in thin silver outline. By 2001, bats were beginning to show up with a modified MLB logo known as the "filled logo." The baseball player within this type of MLB logo has an all silver body from additional foil stamping.

1998 is a lone year of labeling due to the addition of the Major League Baseball logo in 1999 and the different oval found in 1991-97. The only difference between a 1998 gamer and an early 90's gamer is going to be the cenerbrand. The best way to tell them apart is to locate the 125 in the oval. If the i in Louisville and the 1 in 125 are aligned perfectly, then you have a 1998. If the i is rather offset to the right of the 125 closer to the 2, then it is a 1991-97 professional model bat. Please note that some post 98 bats have surfaced with the 1998 label period, and lacking the TPX/MLB logo in the 2002-06 era. While many times it is clear which is the only era, some players have post 98 bats that appear to be 1998's but are not. Louisville Slugger may have left off the TPX/MLB logo on these bats by accident or by player preference.