Ariz. Rev. Stat. § 12-554
A. An owner is not liable for injuries to spectators who are struck by baseballs, baseball bats or other equipment used by players during a baseball game unless the owner either:
D. A registered design professional or a licensed contractor who is involved in the design, construction or operation of the facility is not liable for injuries to spectators who are struck by baseballs, baseball bats or other equipment used by players during a baseball game unless a registered design professional or a licensed contractor either:
F. As used in this section:
3. "Protective seating" means either: