全国ぜんこく高等こうとう学校がっこう野球やきゅう選手せんしゅけん大会たいかいであれば
zenkokukōtōgakkōya kyūsenshukentaikaideareba

Noun
Da Copula

The "-eba" conditional form ("if/when…") of 全国高等学校野球選手権大会

1. If the National High School Baseball Championship…; If there were a National High School Baseball Championship…

Ba Conditional