Rough guess, untested: 

@data = sort {
  $a->[8] <=> $b->[8] or
  $a->[12] <=> $b->[12] or
  $a->[11] <=> $b->[11]
} @data;

[download]
I'm missing a second check against index 11, but I don't have any idea why you're sorting on the same field twice, and it's a bit convoluted for me right now :-)

In reply to Re: Need help making my Merge Sort implementation stable by Tanktalus
in thread Need help making my Merge Sort implementation stable by taffer

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