AllAll Little Leaguers can only partAll Little Leaguers can only participate in ONE T-Mobile Little League Home Run Derby local competition. This provides equal opportunity for all participants to advance to the Regional Events.icipate in ONE T-Mobile Little League Home Run Derby local competition. This provides equal opportunity for all participants to advance to the Regional Events.All Little Leaguers can only participate in ONE T-Mobile Little League Home Run Derby local competition. This provides equal opportunity for all participants to advance to the Regional Events. Little Leaguers can only participate in ONE T-Mobile Little League Home Run Derby local competition. This provides equal opportunity for all participants to advance to the Regional Events.