“You can’t steal second base while your foot is on first base” is a popular business proverb that uses baseball language. “Progress always involves risk. You can’t steal second and keep one foot on first base” was written in March 1924 by Robert Quillen (1887-1948), an American journalist and humorist. Quillen used the same saying again in August 1927, prefaced with “Every big venture involves some risks.”
 
To steal second base in baseball, a player must take a foot off of first base (and risk getting thrown out). The saying is not technically accurate, however; a runner on first base usually takes a lead (and takes a foot off of first base), whether a steal is intended or not.
 
Frederick B. Wilcox, editor of A Little Book of Aphorisms (1947), has been credited with the saying in books and on websites since at least the 1990s, but it’s likely that Wilcox simply compiled Quillen’s saying.
 
   
Wikipedia: Robert Quillen
Verni Robert Quillen (March 25, 1887 - December 9, 1948) was an American journalist and humorist who for more than a quarter century was “one of the leading purveyors of village nostalgia” from his home in Fountain Inn, South Carolina.
 
27 March 1924, The Evening Repository (Canton, OH),  “Editorial Epigrams” by Robert Quillen, pg. 4, col. 6:
Progress always involves risk. You can’t steal second and keep one foot on first base.
 
Google News Archive
11 August 1927, Spartanburg (SC) Herald, “Corks and Curls” by Robert Quillen, pg. 4, col. 5:
Every big venture involves some risks. You can’t steal second and keep one foot on first.
   
Google News Archive
10 August 1934, Meriden (CT) Daily Journal, pg. 6, col. 3:
Progress always involves risks. You can’t steal second base and keep one foot on first.
 
OCLC WorldCat record
You can’t steal second with your foot on first!
Author: Burke Hedges
Publisher: Tampa, FL : INTI Pub., 1995.
Edition/Format:  Book : English : 1st ed
 
Google Books
Quotable Quotes
By Editors of Reader’s Digest
Pleasantville, NY: Reader’s Digest
1997
Pg. ?:
You can’t steal second base and keep your foot on first.
—FREDERICK B. WILCOX
   
Google Books
The Dictionary of Modern Proverbs
By Charles Clay Doyle, Wolfgang Mieder and Fred R. Shapiro
New Haven, CT: Yale University Press
2012
Pg. 224:
You can’t steal second base while your foot is on first base (if you keep one foot on first).
1942 “Shorthand Practice Material” (passages of text to be transcribed),Business Education World 22: “Progress always involves risks. You can’t steal second base and keep your foot on first” (credited to Rays of Sunshine). Dictionary of American Proverbs 529.