The developer advising Chicago's mayor is proposing a $2.2-billion renovation proposal that includes a glass stadium dome to keep the city's National Football League team, the Bears, at its longtime downtown location, Soldier Field. The website Front Office Sports published details Jan. 8. The news is of peripheral interest to horse racing enthusiasts, because the Bears have otherwise entered into a purchase agreement to instead build a $5-billion stadium on the site of the former Arlington International Racecourse. Although the specifics of the proposal are new, city officials have been...