noun
winning streak; string of wins
Used when someone keeps winning without a loss, often in sports or games. The っぱなし ending implies a continuous, uninterrupted state.
彼は今月、勝ちっぱなしだ。
He's been on a winning streak this month.
このチームは開幕から勝ちっぱなしで、まだ負けていない。
This team has been winning straight since the season opener and hasn't lost yet.
連勝 is a more formal term for consecutive wins, often used in statistics or records. 勝ちっぱなし is more colloquial and emphasizes the ongoing, unchecked nature of the wins.
Compound of 勝ち (the continuative form of 勝つ, 'to win') + っぱなし (a suffix indicating a state continues without change).