オープンせん
exhibition game; preseason game
Common word
Noun
オープン戦せんだけ絶好調ぜっこうちょうだった。
He was doing really well in the preseason, but that was it.
オープン戦せんが終おわり、いよいよ開幕かいまくだ。
The exhibition games are over and the regular season finally begins.