Jewish people, allegedly, are not good at sports. A popular Jewish joke is:
 
Q: What’s the world’s thinnest book?
A: “Great Jewish Athletes.”
 
The joke has been cited since at least 1980, but probably dates to the 1960s or 1970s. However, in the 1920s and 1930s and 1940s—especially pre-Jackie Robinson—there were many Jewish sports stars in baseball, basketball and boxing. There is a Wikipedia list of Jews in sports.
         
   
IMDb.com (The Internet Movie Database)
Airplane! (1980)
Quotes
Elaine Dickinson: Would you like something to read?
Hanging Lady: Do you have anything light?
Elaine Dickinson: How about this leaflet, “Famous Jewish Sports Legends?”
 
Newspapers.com
7 December 1990, The Wisconsin Jewish Chronicle (Milwaukee, WI), “When two Mickey Mantles can’t get one Mike Epstein,” pg. 42:
Q: What’s the world’s thinnest book? A: “Great Jewish Athletes.”
 
Google Books
Five Minutes to Midnight:
Race and Sport in the 1990s
By Richard Edward Lapchick
Lanham, MD: Madison Books
1991
Pg. 233:
You sometimes hear a joke told that the world’s shortest book would be the book of Jewish sports heroes. It is surprising for many to discover that Jewish players dominated basketball in the 1920s and 1930s.
 
Washington (DC) Post
A TRIBUTE TO THE STARS OF DAVID
By George Robinson October 18, 1992
ELLIS ISLAND TO EBBETS FIELD Sports and the American Jewish Experience By Peter Levine Oxford University Press. 328 pp. $25
 
HERE’S an old joke that goes: “What’s the shortest book in the world? Great Jewish Sports Heroes.” As historian Peter Levine amply documents in his new book, Ellis Island to Ebbets Field, that’s just not true.
       
Goole Groups: rec.humor
Need “Thinnest Books” Jokes
David Feuer
12/29/94
(...)
How about
1. “Famous Polish Intellectuals”
2. “Famous Jewish Sports Heroes”
 
Google Groups: rec.humor
THE THINNEST BOOK
Ian R. Campbell
11/11/95
.(JavaScript must be enabled to view this email address) (Brother Finneus B Clarkes Jr. Esquire IV) writes:
>This is definately the thinnest book ever written:
>Negro Yachtsmen I Have Known
 
Not quite,there are many colored men who own yachts,such as sports heroes.
Here is what I consider the thinnest book,
Jewish Sports Heroes
 
Google Books
American Sports:
An Anthropological Approach
By Alan Klein
New York, NY: Routledge
2008
Pg. 239:
We all have heard the jokes about the world’s shortest book being titled, Jewish Sports Heroes, and so forth.
 
Sports Illustrated
November 12, 2012
A Distinguished Lineup
No joke—a new collection focuses on Jews in sports
By Alex Belth
A seven-year-old boy looked over my shoulder on the subway and saw that I was reading a book called Jewish Jocks. “Is that a book about Jewish jokes?” he asked. “No,” I told him, “it’s about Jewish sporting figures.” I told him there are also a lot of funny Jewish comedians, but only one—unfunny—joke about Jewish jocks: “Q. What’s the shortest book ever written? A. Jewish Sports Heroes.”
 
Twitter
Jeff Cohen
‏@jeffcohenexec
@espn all I care about if he’s Jewish to help make the smallest book in history a bit larger. Jewish sports stars. @MelBrooks
7:34 PM - 30 May 2015
 
Twitter
Hanukkah Queen
‏@KweenFeminist
The only Jewish joke I really like is that the book “Jewish sports legends” would be really short because of how bad I suck at sports
8:27 AM - 3 Jul 2015
   
The Jewish Week
A Jewish Ring Cycle
12/08/15
George Robinson
(...)
Surely you all know the old joke that says that the shortest book in the world is “Great Jewish Sports Heroes.”