user23651: My son and I are rank chess amateurs, and we wanted to play our first "real" game where we keep track of moves to analyze later.  We started the game but then realized that the board was reversed (i.e. the black pieces were on rows 1 and 2).  Since we didn't notice until a few moves had been played, we just continued to use this reversed notation for the whole game.
The resulting PGN file doesn't want to import into lichess.  Is there any way to take our "reversed" PGN game file and make it compatible?  Perhaps some automated way to reverse the notation, or alert the PGN importer that the notation is reversed so it can handle it?

user4418: If you set the board up correctly, i.e. "white on the right and queen on her own colour", then you need to flip the letters like this:
a ↔ h
b ↔ g
c ↔ f
d ↔ e
and the numbers like this:
1 ↔ 8
2 ↔ 7
3 ↔ 6
4 ↔ 5
So, if white's first move was to push the pawn in front of the king 2 squares you will have written "d5" or "d7-d5". Using the look-up above change this to "e4" or "e2-e4". Do the same for black's first move. If white's second move was to move the knight nearest the king to the square two in front of the bishop and you have written "Nc6" use the look-up to change this to "Nf3". Work through all the moves changing them according to the look-up. 
If you are a programmer and the game is long it will probably be easier to write a simple program to do this.

user23659: Adding on to Brian Towers' answer, there is a quick way you can script this (assuming you are on Linux or another POSIX system with the tr command):
cat gamelog.txt | tr 'abcdefgh12345678' 'hgfedcba87654321' > gamelog_reversed.txt

Edit: as @wimi said, this will mess up move numbers, so be careful about that. You may want to use cut and paste to seperate only the columns with the moves.

23651: <p>My son and I are rank chess amateurs, and we wanted to play our first "real" game where we keep track of moves to analyze later.  We started the game but then realized that the board was reversed (i.e. the black pieces were on rows 1 and 2).  Since we didn't notice until a few moves had been played, we just continued to use this reversed notation for the whole game.</p>

<p>The resulting PGN file doesn't want to import into lichess.  Is there any way to take our "reversed" PGN game file and make it compatible?  Perhaps some automated way to reverse the notation, or alert the PGN importer that the notation is reversed so it can handle it?</p>
 4418: <p>If you set the board up correctly, i.e. "white on the right and queen on her own colour", then you need to flip the letters like this:</p>

<p>a &harr; h<br>
b &harr; g<br>
c &harr; f<br>
d &harr; e<br>
and the numbers like this:<br>
1 &harr; 8<br>
2 &harr; 7<br>
3 &harr; 6<br>
4 &harr; 5</p>

<p>So, if white's first move was to push the pawn in front of the king 2 squares you will have written "d5" or "d7-d5". Using the look-up above change this to "e4" or "e2-e4". Do the same for black's first move. If white's second move was to move the knight nearest the king to the square two in front of the bishop and you have written "Nc6" use the look-up to change this to "Nf3". Work through all the moves changing them according to the look-up. </p>

<p>If you are a programmer and the game is long it will probably be easier to write a simple program to do this.</p>
 23659: <p>Adding on to Brian Towers' answer, there is a quick way you can script this (assuming you are on Linux or another POSIX system with the <code>tr</code> command):</p>

<pre><code>cat gamelog.txt | tr 'abcdefgh12345678' 'hgfedcba87654321' &gt; gamelog_reversed.txt
</code></pre>

<p>Edit: as @wimi said, this will mess up move numbers, so be careful about that. You may want to use <code>cut</code> and <code>paste</code> to seperate only the columns with the moves.</p>
