君の負けだ

you lose

→ 君
phrase Rare #38,622
you lose Literally, “it’s your loss.” 君 is a familiar or somewhat condescending way to say “you,” and だ gives the phrase a blunt, assertive tone. Often used when declaring the outcome of a contest, argument, or situation.
JA: これ以上言い訳しても、君の負けだ。
EN: Even if you keep making excuses, you lose.

では君の負けだ

Well then... you lose.

— インディ・ジョーンズ/最後の聖戦 (1989)

君の負けだ

Looks like you lose.

どちらにせよ君の負けだ

Either way, you lose.