The phrase "dumb luck" means that something good or lucky happened by chance or accident, without any skill, intelligence, or effort involved. Full definition
If it's not, it's just dumb luck on the attorney's part. (ungerandkowitt.com)
Without those 2 things you could mail 10,000 per month and by dumb luck land a deal but that is not how to run and effective business and maximum returns and profits. (biggerpockets.com)
There's a bit of dumb luck involved too. (moneysense.ca)