blow (n.1)youdaoicibaDictYouDict
"hard hit," mid-15c., blowe, from northern and East Midlands dialects, perhaps from Middle Dutch blouwen "to beat," a common Germanic word of unknown origin (compare German bleuen, Gothic bliggwan "to strike"). Influenced in English by blow (v.1). In reference to descriptions or accounts, blow-by-blow is recorded from 1921, American English, originally of prize-fight broadcasts.
LIKE a hungry kitten loves its saucer of warm milk, so do radio fans joyfully listen to the blow-by-blow broadcast description of a boxing bout. ["The Wireless Age," December 1922]