noun
favorable odds; winning momentum; advantageous position
Refers to a situation where one has the upper hand or is likely to win, often in competitive contexts such as sports, games, or battles. The gloss 'favorable odds' captures the sense of a high probability of victory.
試合は終始、我がチームの勝勢で進んだ。
The match proceeded with our team in a winning position from start to finish.
勝勢に乗って一気に攻め込んだ。
Riding the momentum of victory, we pressed the attack all at once.
Compound of 勝 (shō, 'victory') and 勢 (sei, 'force, momentum'). The exact historical derivation is uncertain, but the word is conventionally associated with the idea of a winning trend or favorable odds.