Wiktionary
vb. (context idiomatic English) To fail in one's responsibility or duty, or to make a mistake, especially at a critical point or when the result is very negative.
Usage examples of "drop the ball".
Number One grabbed one of the soft holding straps on the wall and waited for the catch trap to drop the ball down to the launcher and snap it into play again.
Your tricks may be artful enough here, but if you drop the ball in there, the rest of us are left plowing the north field with our God-given hoe, if you catch my drift.
Archer had always had his doubts about the Squids' suitability to run what obviously should have been an Air Force command properly, but he'd never seriously expected them to drop the ball this badly.
Archer had always had his doubts about the Squids suitability to run what obviously should have been an Air Force command properly, but hed never seriously expected them to drop the ball this badly.
I don't expect the greatest impact to be here at home, unless we really drop the ball.