Your regexes make it look like you are reading large portions of the log at one time (or maybe even slurping it?). Why?

If the log format is reliably consistent with the example you gave, a simple line-by-line reading should be plenty easy, quick and maintainable; and it looks like the kind of situation where a hash data structure would be handy:

#!/usr/bin/perl

use strict;
use warnings;
use Data::Dumper;

my @fieldnames = (
                  'Team', 'Score', 'Player', 'Kills', 'Deaths',
                  'Team Kills', 'Suicides', 'Objective', 'Results for 
+Map'
                 );
my $matchfield = join '|', @fieldnames;

my %entry;
my ( $map, $team, $player, $datafor );

while (<DATA>) {
    s/[\r\n]+//;  # OS-neutral alternative to "chomp"

    my ( $timestamp, $data ) = unpack( "A26 A*", $_ );
    next unless ( length( $data ) and $data =~ /$matchfield/ );

    $timestamp =~ tr/[]//d;
    my ( $fieldname, $fieldval ) = split( /: /, $data, 2 );
    $fieldname =~ s/^[\s*]+//;

    if ( $fieldname eq 'Results for Map' ) {
        processEntry( \%entry );
        %entry = ();
        $entry{map} = $fieldval;
        $entry{time} = $timestamp;
    }
    elsif ( $fieldname eq 'Team' ) {
        $datafor = $fieldname;
        $team = $fieldval;
        $entry{$team} = {};
    }
    elsif ( $fieldname eq 'Player' ) {
        $datafor = $fieldname;
        my $uid;
        ( $player, $uid ) = ( $fieldval =~ /(\w+) .uid: (\w+)/ );
        $entry{$team}{$player}{uid} = $uid;
    }
    elsif ( $fieldname eq 'Score' ) {
        if ( $datafor eq 'Team' ) {
            $entry{$team}{Score} = $fieldval;
        } else {
            $entry{$team}{$player}{Score} = $fieldval;
        }
    }
    else {
        $entry{$team}{$player}{$fieldname} = $fieldval;
    }
}
processEntry( \%entry );

sub processEntry
{
    my $href = shift;
    return unless ( scalar keys %$href );
    print Dumper $href;
}

__DATA__
[Thu Sep 21 17:48:38 2006] 
[Thu Sep 21 17:48:38 2006] ------------------------------------------
[Thu Sep 21 17:48:38 2006] Server started.
[Thu Sep 21 18:37:22 2006] Client connected: Alpha
[Thu Sep 21 18:37:31 2006] Client connected: Bravo
[Thu Sep 21 18:38:20 2006] Client connected: Charlie
[Thu Sep 21 18:39:18 2006] Client connected: Delta
[Thu Sep 21 18:53:36 2006] 
[Thu Sep 21 18:53:36 2006] *** Results for Map: Worlds\ReleaseMultipla
+yer\Bypass
[Thu Sep 21 18:53:36 2006] 
[Thu Sep 21 18:53:36 2006] Team: Team 1
[Thu Sep 21 18:53:36 2006] Score: 93
[Thu Sep 21 18:53:36 2006] 
[Thu Sep 21 18:53:36 2006] Player: Alpha (uid: ad7023b7f46271acd31e1bd
+287613b6d)
[Thu Sep 21 18:53:36 2006] Score: 55
[Thu Sep 21 18:53:36 2006] Kills: 14
[Thu Sep 21 18:53:36 2006] Deaths: 15
[Thu Sep 21 18:53:36 2006] Team Kills: 0
[Thu Sep 21 18:53:36 2006] Suicides: 0
[Thu Sep 21 18:53:36 2006] Objective: 0
[Thu Sep 21 18:53:36 2006] 
[Thu Sep 21 18:53:36 2006] Player: Bravo (uid: 5fdcc95043dc4dac9d7b4af
+b8469eb4f)
[Thu Sep 21 18:53:36 2006] Score: 38
[Thu Sep 21 18:53:36 2006] Kills: 11
[Thu Sep 21 18:53:36 2006] Deaths: 17
[Thu Sep 21 18:53:36 2006] Team Kills: 0
[Thu Sep 21 18:53:36 2006] Suicides: 0
[Thu Sep 21 18:53:36 2006] Objective: 0
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