“Study long, study wrong” has been used in many sports and games, such as dominoes, cards, checkers, golf, billiards and horse racing. “If you study long, you study wrong” has been cited in print since at least 1919.
   
 
Urban Dictionary
study long study wrong
hood slang
1. to overthink something
2. or to try to force an idea out.
Usually said to the person taking forever…
domino player 1:hmmm…....
domino player 2:study long study wrong nigga!
by kilo Mar 24, 2006
 
6 April 1919, Denver (CO) Post, pg. 4, col. 5:
If you study long, you study wrong. Why not get that refrigerator today and be prepared for the hot summer day to come.
(Davis & Shaw—ed.)
 
18 March 1933, The Spokesman (Chicago, IL), “The Week” by Roscoe Simmons, pg. 1, col. 1:
You have heard the old saying, “Haste makes waste.” There is another, too. It is, “Study long, study wrong.”
 
Google Books
Reading for Writing
By Ivan E. Taylor
New York, NY: Ronald Press Co.
1952
Pg. 10:
We use them now to a limited degree (“Here today; gone tomorrow”; “Study long; study wrong”) in slang and trite parodies of wisdom.
 
12 April 1953, Augusta (GA) Chronicle, magazine, pg. 10, col. 1:
‘study long, study wrong’?
“Like many another axoim, this one is steeped in fallacy—especially in marital matters” ... says Beatrice (Illegible—ed.)
(...)
Recently, his aunt said to me: “Study long, study wrong,” meaning that I might lose him.
 
Google Books
How to Coach and Play Championship Golf
By Dave Williams
Englewood Cliffs, NJ: Prentice-Hall
1962
Pg. ?:
I’m a firm believer in the old adage, “study long, study wrong.”
 
21 April 1970, New Orleans (LA) Times-Picayune, “Barber Birdies No. 2 to Win GNOO” by Bob Roesler, sec. 3, pg. 1, col. 4:
Barber, apparently a believer that to study long is to study wrong, quickly sized up his putt and swung that putter of his.
 
13 May 1974, Morning Star (Rockford, IL), “When ‘PG’ breaks even he wins” by Bob Hill, pg. 3:
“Study long, study wrong,” Pg tells him.
(Horse racing—ed.)
   
Google Books
Teach Your Self Pool
By Christos E. Raftis
Detroit, MI: C.R. Billiards
1991
Pg. 287:
STUDY LONG AND YOU STUDY WRONG.
When you first approach the table and read the table, you will make judgements.
     
Google Books
Coffee Will Make You Black
By April Sinclair
New York, NY: Harper
1994
Pg. 109:
“You study long, you study wrong,” Grandma said as I stared at the checkerboard.
 
Google Books
Bear-proof Investing:
Protecting your financial future in a bear market and taking advantage of an emerging bull market
By Ken Little
Indianapolis, IN: Alpha
2002
Pg. 199:
My grandfather had a saying about spending too much time worrying about a decision: “You study long, you study wrong.” (I usually heard this while trying to figure my next move in a game of dominoes with him.)
   
Google Books
1000 Best Poker Strategies and Secrets
By Susie Isaacs
Naperville, IL: Sourcebooks
2006
Pg. 236:
There is an adage in hold’em: “If you study long, you study wrong.”
 
Google Books
By a Nose:
Gambling tales from a horseracing insider
By Jim Gentile
Xlibris
2008
Pg. 154:
My Uncle Dick was fond of saying “study long, study wrong,” but that was exactly what we did.