#!/usr/bin/perl -w
use strict;

my %hash;
# Do it
for (<DATA>) {
   my ($name, $score, $date) = split /\|/;
   $hash{$name}++;
}
#Show it
for (keys %hash) {
   print "$_ = $hash{$_}\n";
}
__DATA__
name_x|score|date
name_y|score|date
name_z|score|date
name_x|score|date
name_z|score|date
name_z|score|date

##</code><code>##

$name{(split/\|/)[0]} += 1;