When you buy through our links, Business Insider may earn an affiliate commission. Learn moreCaitlin Clark (left); Breanna Stewart (right)Gregory Shamus/Getty Images (left); AP Photo/Wade Payne (right)It's a no. 1 pick showdown tonight in the WNBA, with Caitlin Clark and Breanna Stewart squaring off in the Indiana Fever's first home game of the regular season.