steal a march on - Phrases/Idioms
The American Heritage® Dictionary of Idioms by Christine Ammer. Copyright © 2003, 1997 by The Christine Ammer 1992 Trust. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Gain an advantage over unexpectedly or secretly, as in Macy's stole a march on their rival department store with their Thanksgiving Day parade. This metaphoric expression comes from medieval warfare, where a march was the distance an army could travel in a day. By quietly marching at night, a force could surprise and overtake the enemy at daybreak. Its figurative use dates from the second half of the 1700s.