user13981: I've started to code my own little engine recently and am now working on a perft function which simply sees how many moves there are.
Trying to get correct results I searched online for the correct amount of possible positions after e.g. 4 moves.
Now according to these sources: 
https://youtu.be/6Y_FaQhqX2c?t=5m46s
It should be 197281 possible positions after 4 moves, and I can reach that in my code!
But switching a bit around in my code to get some optimization which seemingly shouldn't change anything, I get a different number: 197742
Now I would think that is wrong but I have found different sources again, claiming that is in fact correct:
https://youtu.be/Km024eldY1A?t=5m33s
So, which one is it? 197742 or 197281 possible positions after 4 moves?
I was a bit uncertain whether this belongs here or on StackOverflow.
I went with this one, I hope that's alright.
EDIT: apparently I can't post more than two links due to my low reputation
I'll post the links in comments
Thanks in advance
Folling

user825: The chess programming wiki is correct:

https://chessprogramming.wikispaces.com/Perft+Results

197281 is the number. I remember I used Stockfish to generate the same number while debugging my code.

13981: <p>I've started to code my own little engine recently and am now working on a perft function which simply sees how many moves there are.
Trying to get correct results I searched online for the correct amount of possible positions after e.g. 4 moves.
Now according to these sources: </p>

<p><a href="https://youtu.be/6Y_FaQhqX2c?t=5m46s" rel="nofollow noreferrer">https://youtu.be/6Y_FaQhqX2c?t=5m46s</a></p>

<p>It should be 197281 possible positions after 4 moves, and I can reach that in my code!</p>

<p>But switching a bit around in my code to get some optimization which seemingly shouldn't change anything, I get a different number: 197742
Now I would think that is wrong but I have found different sources again, claiming that is in fact correct:</p>

<p><a href="https://youtu.be/Km024eldY1A?t=5m33s" rel="nofollow noreferrer">https://youtu.be/Km024eldY1A?t=5m33s</a></p>

<p>So, which one is it? 197742 or 197281 possible positions after 4 moves?
I was a bit uncertain whether this belongs here or on StackOverflow.
I went with this one, I hope that's alright.</p>

<p>EDIT: apparently I can't post more than two links due to my low reputation
I'll post the links in comments</p>

<p>Thanks in advance
Folling</p>
 825: <p>The chess programming wiki is correct:</p>

<blockquote>
  <p><a href="https://chessprogramming.wikispaces.com/Perft+Results" rel="nofollow noreferrer">https://chessprogramming.wikispaces.com/Perft+Results</a></p>
</blockquote>

<p>197281 is the number. I remember I used Stockfish to generate the same number while debugging my code.</p>
