"If it’s low, let it go; if it’s high, let if fly” is advice on hitting the knuckle ball. If the ball is low, it often sinks into the dirt. “‘If it’s low, let it go. If it’s high, let it fly,’ Kirby Puckett explained” was cited in print in 1989.
17 April 1989, St. Paul (MN) Pioneer Press, “Gaetti sinks Yanks with 6 RBIs,” pg. 1E:
“If it’s low, let it go. If it’s high, let it fly,” Kirby Puckett explained.
16 April 1993, Miami (FL) Herald, “Astros all aflutter about knuckler,” pg. 5D:
“The knuckleball philosophy I always heard was, ‘If it’s low, let it go; if it’s high, let it fly,’” Bagwell said
6 June 1993, San Jose (CA) Mercury News, “Wilson retires homer bat,” pg. 7D:
‘’Against knucklers,” Williams said, “they say if it’s low, let it go. And if it’s high, let it fly.”
27 September 2001, Philadelphia (PA) Daily News, “We’ll take 10 more games like that,” Sports, pg. 120:
Bowa said, “The motto on the knuckleball is, ‘If it’s high let it fly, if it’s low let it go.’”
September 03, 2007
Hitting A Knuckleball With ...
Orioles First Baseman Kevin Millar
(Millar has hit .474 with two home runs in 19 career at bats against Red Sox knuckleballer Tim Wakefield.) “It’s the old theory: If it’s high, let it fly; if it’s low, let it go. Most of the time when it’s low, it’s going to go down in the dirt. It never stays on a plane.”
How to hit a knuckleball
by Scott Butler 5/25/10
However, like most pitches, if you leave the knuckleball up it is a completely different story. Now I understand the saying, “If it’s high let it fly, if it’s low let it go.” High knuckleballs don’t like to dance much, and a knuckler with no movement is like a slow pitch softball and you can just hack away.
If it’s low let it go, if it’s high let it fly. Knuckleball Rules. #RedSox
10:18 AM - 7 Apr 13