Vintage Baseball BatsThe bulk of the value on most collectible Baseball bats relies on player endorsements. Without a player endorsement, the value will rely on vintage baseball bat features such as a decal, or special features such as a mushroom knob, a ring bat, ornate engraving, etc. Age and condition will effect the value as well. Hillerich & Bradsby Co. Louisville Slugger has used different oval center brands in their history. By identifying the center label, trade marks, and patens you can narrow down the year to what era the bat was made.