I looked into Iowa's 1000 wins and separated the winds per venue. Here are the stats for you.
Close Hall 1901-1905
11 wins 3 losses 79% win rate.
Old Armory (later became the library annex) 1905-1920
75 wins 39 losses 66% win rate.
The Armory (would later adjoin Fieldhouse) 1920-1927...
Is there an active group to oppose the university's plans to demolish the historic Iowa Fieldhouse? That building has more history than most any in the state. I would also like to see it saved as a practice facility and backup sports venue. The university should stop building new facilities...