Also, get or have the jump on. Achieve a distinct advantage over someone, especially through early or quick action; get a head start. For example, Their book on electronic communication has the drop on all the others, or We really got the jump on the competition. The first of these slangy expressions dates from the mid-1800s and originally alluded to pointing one's gun at someone before he pointed his at you. It was transferred to more general use by about 1900. The second, which uses jump in the sense of “start,” dates from about 1900.
The American Heritage® Idioms Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.