Here is a solution that doesn't create any temp values and it keeps all your information in order in an array. A hash is in my opinion the easier way to count the occurances.

use Data::Dumper;
my @all;
my %occurance;
while (<DATA>) {
    chomp;
    push @all, [ split(/\|/,$_) ];
    $occurance{$all[-1][0]}++;
}

print Dumper(\@all);
print Dumper(\%occurance);

__DATA__
name_x|score|date
name_y|score|date
name_y|score|date
name_z|score|date
name_z|score|date
[download]

I included the Data::Dumper part for monks that haven't used it yet so they can see how it can be used to confirm content without doing a foreach or similar operation to see content of a hash or array.