They are trying to raise the level from that of the amateurs to the professionals.
"They are trying to raise the level"＝「彼らはレベルを上げようとしている」
"from that of the amateurs to the professionals"＝「アマチュアからプロのに」
Sentence in context:
"They are trying to raise the level of the juries of this sport from that of an amateur to a professional."
アメリカ合衆国 
