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copied!<p>This is a common way to botch the <a href="http://en.wikipedia.org/wiki/Fisher%E2%80%93Yates_shuffle" rel="nofollow noreferrer">Fisher-Yates shuffle algorithm</a>. See <a href="https://stackoverflow.com/questions/5131341/what-distribution-do-you-get-from-this-broken-random-shuffle/5320428">What distribution do you get from this broken random shuffle?</a> for a lively discussion on properties of this implementation.</p> <hr> <p><strong><em>How is this different from Fisher-Yates?</em></strong></p> <p>For Fisher-Yates, at the <code>k</code>th card you must choose a random number between <code>k</code> and <code>52</code>. You are choosing a random number between <code>1</code> and <code>52</code> each time.</p> <hr> <p>The method you describe is similar to that discussed in <a href="https://stackoverflow.com/questions/5131341/what-distribution-do-you-get-from-this-broken-random-shuffle/5320428">What distribution do you get from this broken random shuffle?</a>, but may not be exactly the same. Your implementation is similar to the well studies "Top to Random" shuffle (see <a href="http://journals.cambridge.org/action/displayAbstract;jsessionid=EA72A81A5646929427D99E6A18A65F7F.tomcat1?fromPage=online&aid=1771344" rel="nofollow noreferrer"><em>Analysis of Top To Random Shuffles</em></a> by Diaconis, Fill and Pitman) that will eventually give a fully shuffled deck, though not in "one pass". The Top to Random shuffle is described as following:</p> <blockquote> <p>Choose a random number <code>p</code> from <code>1</code> to <code>52</code>, and swap the top card with the card at position <code>p</code>. Continue until the top card is the card originally in position <code>52</code>, and after this is randomly placed the deck is in random order.</p> </blockquote> <p>This stop condition is known as a "Stopping Time", and takes quite a while to attain. The Fisher-Yates shuffle is far faster.</p>

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