当あてが外はずれる

expression, ichidan verb

to be contrary to one's expectations; to go wrong; to miss the mark

Used when a plan, hope, or expectation does not come true. Often implies disappointment or a miscalculation.

• 天てん気き予よ報ほうが外はずれて、当あてが外はずれた。

  The weather forecast was wrong, and things didn't go as expected.

• 彼かれが来くると思おもっていたのに、当あてが外はずれた。

  I thought he would come, but my expectation was off.