This article will deal with how to authenticate Mark McGwire game used bats. Mac started in the majors in 1986. In his early years (and the minors) he used both Louisville Slugger and Rawlings (Adirondak) Big Stick bats. But later switched over exclusively to Rawlings Big Stick exclusively. His Rawlings/Adirondak bats have all been 34.5 inches in length and 33 ounces. I have seen both 34 and 34.5 inch Louisville Sluggers though, but most were 34.5. There are four different types of bat markings to look for when buying a gamer. They can tell a lot about the authenticity of the bat. they also can give you the year it was used as well as who it was issued to. These markings are: 1) barrel markings, 2) knob markings 3) personalizations, and 4) game use markings. I will discuss each of these to some detail.

BARREL MARKINGS

1986

When Mac came up in 1986 the barrel of his bats would have been marked as such (figure 1, below) for a Big Stick model. This was the case only for an '86 model bat. Notice the wording "professional model" under the players name. This would not change until after '89. Also all Mac gamers were the "green ring" variety for the teams colors. this would appear on all his gamers until he was traded in '97. An early ('86-'87) model Louisville Slugger would have looked like this (figure 2, below) or this (figure 3, below). I believe that the Louisville Slugger models were only used in '86 or '87. I have no evidence that he used them after that.

1987 thru 1989

In 1987 Rawlings (Adirondak) changed their barrel logo to this type (figure 4) and it remained that way through 1989. Notice the new "Pro Ring" logo. During this period Mac was voted to different All Star teams as well as appeared in the ALCS and World Series. Rawlings also had special bats made up for these events which had the event listed under the players name instead of "professional model" (figure 5).

1990 thru 1996

In 1990 Rawlings changed the barrel once again. It removed the "pro ring" insignia and replaced the words "professional model" with the players team name. In Mac's case it said "OAKLAND A'S" under his name.(figure 6). The All Star, ALCS and World Series models would now have the event listed ABOVE the players name where its had said "Big Stick"( figure 7).

1997 to Present

In 97 Rawlings totally overhauled the bat logo's. Instead of saying Rawlings on the barrel they just had a big "R" inside an oval (figure 8). Of course in '97 Mac got traded to St Louis so after the trade his bats got a red ring and "Cardinals" was printed under his name. (figure 9)