ほらがとうげをきめこむ

To wait and see how things play out

Decide決込 upon the outcome of Horagatouge洞ヶ峠 At the battle of Yamazaki, Tsutsui Junkei(筒井順慶) waited to see which army gained the upper hand at Horagatouge, which lies on the border of Kyoto and Osaka