勝てっこない

can't possibly win, have no chance of winning

→ 勝つ
勝て potential form (can win) + っこ emphatic impossibility + ない Negative
verb · potential Rare #40,448
can't possibly win, have no chance of winning An emphatic, colloquial way to say that winning is impossible or highly unlikely.
JA: あんな強い相手には勝てっこない。
EN: We can't possibly beat an opponent that strong.
Conjugation of 勝つ
Potential

勝てっこない

There’s no way we can win.

どうせ勝てっこない

There's no way we'll win anyway.

絶対勝てっこないって

There's absolutely no way we can win.

やらなきゃ勝てっこない

If you don't do it, there's no way you'll win.