What is "slap shots"

Usage examples of "slap shots".

There were pictures of thoroughbreds crashing toward finish lines, running backs smashing into end zones, soccer players making head contact with flying balls, masked goalies deflecting slap shots, a bowler goosing air with his thumb while a triangle of pins blew apart, many glossy photos of baseball greats diving at bases, fielding impossible drives, swinging blurred bats against blurred balls.