user-1: 
In the history of sport — and publishing — it’s not even close: one sport has had more books (and for that matter, magazines, tracts, pamphlets and handbills) published about it far more than any other: Chess.

Source: publishingperspectives.com
I often hear, but have never seen justification for, the claim that there are more books published on chess than any other sport.
My questions are:

Is this true?
What are the origins of the claim?


user-1: Is the claim true?
No. Using the Google Books Library Project, there are:

233,000 results for Chess
987,000 results for Sport
472,000 results for Football

Where does the claim come from?
From Wikipedia, the claim likely originated from H. J. R. Murray in 1913:

In 1913, preeminent chess historian H. J. R. Murray wrote in his 900-page magnum opus A History of Chess that, "The game possesses a literature which in contents probably exceeds that of all other games combined."


user11177: The below answer is incorrect because it includes newspapers and magazines. If you go under "Advanced search" and do the same search string, you can see that the results reported on the main page include magazines and newspapers. After omitting these, google search does not give a number of results. 
It stands to reason that there will be a large number of newspaper and magazine accounts about football. 

-1: <blockquote>
  <p>In the history of sport — and publishing — it’s not even close: one sport has had more books (and for that matter, magazines, tracts, pamphlets and handbills) published about it far more than any other: Chess.</p>
</blockquote>

<p>Source: <a href="http://publishingperspectives.com/2015/09/chess-the-worlds-most-published-sport/#.V9Exz_krLrc">publishingperspectives.com</a></p>

<p>I often hear, but have never seen justification for, the claim that there are more books published on chess than any other sport.</p>

<p>My questions are:</p>

<ol>
<li>Is this true?</li>
<li>What are the origins of the claim?</li>
</ol>
 -1: <h2>Is the claim true?</h2>

<p><strong>No</strong>. Using the <a href="https://books.google.co.uk/" rel="nofollow">Google Books Library Project</a>, there are:</p>

<ul>
<li>233,000 results for <a href="https://www.google.com/search?tbm=bks&amp;q=chess" rel="nofollow">Chess</a></li>
<li>987,000 results for <a href="https://www.google.com/search?tbm=bks&amp;q=chess#tbm=bks&amp;q=sport" rel="nofollow">Sport</a></li>
<li>472,000 results for <a href="https://www.google.com/search?tbm=bks&amp;q=chess#tbm=bks&amp;q=football" rel="nofollow">Football</a></li>
</ul>

<h2>Where does the claim come from?</h2>

<p>From <a href="https://en.wikipedia.org/wiki/Chess_theory" rel="nofollow">Wikipedia</a>, the claim likely originated from H. J. R. Murray in 1913:</p>

<blockquote>
  <p>In 1913, preeminent chess historian H. J. R. Murray wrote in his 900-page magnum opus A History of Chess that, "The game possesses a literature which in contents probably exceeds that of all other games combined."</p>
</blockquote>
 11177: <p>The below answer is incorrect because it includes newspapers and magazines. If you go under "Advanced search" and do the same search string, you can see that the results reported on the main page include magazines and newspapers. After omitting these, google search does not give a number of results. </p>

<p>It stands to reason that there will be a large number of newspaper and magazine accounts about football. </p>
