"Repairs - Many cracked bats or bats with missing pieces are, at some point, repaired in one of two ways. There is professional repair and non-professional repair. When a crack is repaired professionally, most collectors cannot detect it. Unlike the sportscard market, professional repair is not frowned upon in the bat market because condition is not viewed in the same light. In fact, professional repair can really improve the eye appeal of a gamer. Non-professional repair such as batboy repair or collector repair may also be a factor. Batboys, in days past, were routinely instructed to repair player bats in the dugout by using nails. Many collectors feel that the presence of batboy repairs adds a vintage feel to the piece while others may not like the look. Collector repairs are, for the most part, accepted as long as the repair was not done in a reckless manner."
