～戦
～せん · ～sen · JLPT N2 · noun
game
⚔️ 戦 means battle, so each match counts as one battle: 3戦 = three bouts
The kanji 戦 means war or battle, as in 戦争 (sensō, war). As a counter, each game or bout is one battle. A record like 5戦3勝 means five matches, three wins.