by a long shot

by a long shot  {adv. phr.},  {informal}

By a big difference; by far. — Used to add emphasis.

Bert was the best swimmer in the race, by a long shot.

Often used with a negative.

Tom isn't the kind who would be fresh to a teacher, by a long shot.

Our team didn't win — not by a long shot.

Compare: MISS BY A MILE.