“You can’t hit what you can’t see” is what a frustrated baseball batter says after facing a blazing fastball pitch. “Can’t hit them when you can’t see them” was cited in print in 1907. “You can’t hit what you can’t see” and “when you can’t see ‘em you can’t hit ‘em” were both cited in 1912 and said about the commanding pitching of Walter Johnson (1887-1946). American heavyweight boxing champion Muhammad Ali would also use “you can’t hit what you can’t see” in the 1970s.
 
“You can’t hit what you can’t catch” is both a boxing and a hockey saying. “You can’t beat what you can’t catch” is a horseracing saying.
   
 
5 April 1907, Illinois State Register (Springfield, IL), “Chicago Cubs Come Saturday,” pg. 12, col. 2:
“Can’t hit them when you can’t see them,” will welcome the opposing batters, when they face the invincible twirlers of the Springfield team.
 
Chronicling America
12 June 1912, The Evening Standard (Ogden, UT), “Johnson and Walsh Race,” pg. 9, col. 2:
But, as the players say, “You can’t hit what you can’t see.”
 
12 August 1912, Charleston (SC) Evening Post, “Why Johnson Is A Great Pitcher,” pg. 3, col. 4:
It’s an old saying in baseball, ‘when you can’t see ‘em you can’t hit ‘em.’ That is the case when batters face Johnson.
 
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Left o’ the Blue Stockings
By Bart L. Standish
New York, NY: Barse & Hopkins
1914
Pg. 224:
Peter McLaughlin found it almost impossible to remain on his seat. “You’ve got him!” the old man shouted. “He can’t hit ye, Stranger! He can’t see your fast ones. Give him a curve now, and see what he can do with it.”
 
Chronicling America
25 July 1919, Washington (DC) Herald, “Walter Johnson Proves Too Much for Athletics,” pg. 10, col. 1:
The big Kansas train was shooting them by the visiting batters with so much whiz-bang that even the slugging George Burns and Amos Strunk were forced to repeat what Ty Cobb has many, many times said, “You can’t hit what you can’t see.”
 
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19 November 1924, The Independent (St. Petersburg, FL), “Walter The Great Will Retire From Capital Baseball,” pg. 28, col. 1:
The saying became general in the American league that “You can’t hit what you can’t see,” and the “big train” as he came to be known, thundered along his way.
 
Google News Archive
1 August 1927, The Evening Independent (St. Petersburg, FL), “‘Can’t Hit What they Can’t See’” Once Said of Johnson’s Twirling” by Billy Evans, pg. 11, col. 2:
“Whadda mean curve ball? Say, a guy with the speed of Johnson doesn’t need anything else. You can’t hit what you can’t see. That’s how fast that big busher is.”
 
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August 1932, The Rotarian, pg. 50, col. 2:
It was “Gabby” Street, now managing the World Champion St. Louis Cardinals, then Walter Johnson’s catcher, who coined the expression that has lived on: “You can’t hit what you can’t see.” His reference, of course, was to Walter Johnson’s fast ball.
 
Google News Archive
10 December 1946, Bend (OR) Bulletin, “Walter Johnson Of Baseball Fame Tumor Victim,” pg. 7, col. 2:
It was Johnson’s blazing fast ball that inspired the famed, and unanswerable, baseball alibi—“You can’t hit ‘em when you can’t see ‘em.”
 
Google Books
Walter Johnson, King of the Pitchers
By Roger L. Treat
New York, NY: J. Messner
1948
Pg. 36:
“N o,” he said, “but you can’t hit ‘em if you can’t see ‘em.”
 
A slogan had been coined. It would be repeated millions of times in the years to come. And always it would be associated with Walter Johnson. “You can’t hit ‘em if you can’t see ‘em.”
 
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23 October 1970 The Morning Record (Meriden, CT), “Cassius Clay: You Can’t Hit What You Can’t See,” pg. 12, col. 1:
ATLANTA (AP)—Muhammad Ali mutters constantly that he’s the “fastest” best conditioned heavyweight in history.
(...)
“You can’t hit what you can’t see,” said Ali, his body pumping sweat after Thursday’s workout. “I’m the fastest, and Quarry just ain’t ever fought the fastest before.”
 
Google News Archive
9 October 1974, Beaver County (PA) Times, “Ex-Champ Still Stinging And Floating: Ali Talking It Up Again,” pg. D-2, cols. 2-3:
Looking out across the Zaire river, previously the Congo, Ali started spouting a new bit of verse:
 
“I will float like a butterfly, sting like a bee.
His hands can’t hit what his eyes can’t see.
First he sees me and then he don’t.
He thinks he can catch me, but I know he won’t.
They say he’s good, but I’m twice as nice.
And I will stick to his butt, like white on rice.”