[mattm]

There are a few good articles on this topic on the net if you google a bit, but here are some simple rules to start you out:

1. If it is a H&B bat, the model number should be 125 and the branding should be truly stamped and embedded, not decals or printing. Should also say "Powerized" above the bar ell branding

2. Most important - the knob should be stamped with a straight model number with a letter and a number such as W166 or K55, NOT a number such as 3 or 4 or 5 - those are lengths (33,34,35). Youl also so should NOT see a players initials and some numbers, such as JR3 (a Jackie Robinson 33 inch bat).

3. If the length is less than 34 inches, it is likely not a vintage MLB bat (though some smaller guys today order 33.5" like Pedroia).

4. Watch out for star players, as even if you get the right model, you may have a Team Index Bat. These look like the player bats but were ordered by the team for BP or other general use. Often this is a Pro Stock model such as the W166 for Ted Williams. In order to have a chance at being a true GU bat from a star player, you need to match the year, length and weight to the players Personal Bat Ordering Records (PBOR). So a 34 inch O1 model (Lefty O'Doul model favored by Williams early in his career) H&B bat with 1950's branding would be deemed a Team Index bat since Williams' PBOR does not contain 34 inch bats, just 35 inch bats.

Confused yet? Don't worry, you will disqualify most store bats by looking at the number on the barrel and the knobs as above.

Matt