use strict;
use Data::Dumper;

my $team;
my $player;
my %teamAccts;
my %seen;

while (<DATA>) {
        if (/^T:(\S+)/) {
                $team = $1;
                next;
        }

        if (/^P:(\S+)/) {
                $player = $1;
                push @{$teamAccts{$team}}, $player
                    unless $seen{"$team$player"}++;
        }
}

print Dumper(\%teamAccts);
__DATA__
T:REDS
P:GRIFFEY
P:GRIFFEY
P:PEREZ
P:ROSE
P:BENCH
T:PHILLIES
P:ROSE
P:ROSE
T:MARINERS
P:GRIFFEY
P:PEREZ