Mike! Great info as usual! I appreciate the help. I currently own 31 Biggio GU Bats, dating from the 1986-89 labeling period to 2006 bats from this month.

Obviously, the tough (long) era is 1991-97. Of the 31 bats, 7 are from the 1991-97 labeling period. Here is a breakdown:

3 have "CRAIG BIGGIO" in block letters. These 3 also have the dated tape on the knob from when the Astros sold bats with dated COAs from the late 1980s to Mid-1994 in the team store. These are dated between 5/91 and 7/92.

4 are Craig Biggio signature model bats. One has the dated tape on the knob from 6/94. The other 3 are post the Astros dating practices.

Therefore, I have never owned a "documented" 1993 bat, but have suspected he started using signature model bats sometime between 7/92 and 6/94 based on my collection.

Thanks again for the info!