シーソーゲーム

noun

seesaw game; back-and-forth match

Used mainly in sports contexts for a match where the lead changes repeatedly, like a seesaw.

• 昨日きのうの試し合あいはシーソーゲームで、最さい後ごまでどちらが勝かつかわからなかった。

  Yesterday's match was a seesaw game, and until the very end it was unclear who would win.