This is the 4913th most frequent Japanese word.
白番
"白番" refers to the player or side using white stones in the game of Go.
白番 is used here to specify the side of the player playing with white stones in the Go board game.
囲碁の試合では、白番は先手になります。
In Go games, the white side takes the first move.
白番 is used here by the speaker to state their choice of playing as the white stones side in the context of a game.
私は今回の試合で白番を選びました。
I chose the white side for this match.
白番 refers figuratively to the strategies and planning associated with playing as the white stones side during gameplay.