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Baseball-Sabermetrics-0.03
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/ Baseball::Sabermetrics

NAME

Baseball::Sabermetrics - A Baseball Statistics Module

SYNOPSIS

Baseball::Sabermetrics provides an easy interface for calculating baseball statistics, given a data importer. In this package, I've written CPBL.pm for (Chinese Professional Baseball League, http://www.cpbl.com.tw).

  use Baseball::Sabermetrics;
  use Baseball::Sabermetrics::CPBL;

  my $league = Baseball::Sabermetrics->new(league => 'CPBL');

  # Actually these are predefined.
  # Those data with 'p_' or '_allowed' here are for seperating pitchers
  # and batters.

  $league->define(
      rc => 'ab * obp',
      babip => '(h_allowed - hr_allowed) / (p_pa - h_allowed - p_so - p_bb - hr_allowed',
      # what started with '$' will be reserved.
      # Players have team and league predefined, and team has league.
      formula1 => 'hr / $_->team->hr';
      formula2 => 'hr / $_->league->hr';
      complex => sub {
	    print "You can write a sub directly\n";
	    $_->slg - $_->ba;
      },
      ...
  );

  # Some formulas can be applied to players, teams, and league, depend on what
  # columns are used in the formula.  For example, ab and obp are defined for
  # players, teams, and league, so that rc is available for all of them.

  # top 5 obp of teams
  $_->print qw/ team name ba obp slg isop / for $league->top('teams', 5, 'obp');

  # top 10 obp of players
  $_->print qw/ team name ba obp slg isop / for $league->top('players', 10, 'obp');

  # show a player's information
  $league->players('Chien-Ming Wang')->print qw/ win lose ip so bb whip go_ao /;
  $league->teams('Yankees')->players('Chien-Ming Wang')->print qw/ win lose ip so bb whip go_ao /;

  # show team statistics data (accumulated from players')
  $league->{Yankees}->print qw/ win lose ip so bb whip go_ao /;

  # give a brief report for pitchers/batters of the team
  $league->{Yankees}->report_pitchers qw/ name ip p_so p_bb whip go_ab /;
  $league->{Yankees}->report_batters  qw/ name ba obp slg isop /;

  $league->report_teams qw/ name win lose era obp /;

  # show all available formula
  print join ' ', $league->formula_list;

Data Structure

Baseball::Sabermetrics is aimed for providing a base class of your interested teams (a league, for example). You'll need to provide a data retriever to pull data out. The following example shows how you have to fill data into this structure.

 $league = {
    teams => {
	Yankees => {
	    players => {
		"Chien-Ming Wang" => {
		    bio => {
			bats => 'right', # coule be left, switch
			throws => 'right',
		    },
		    ip => 57.33333333333,
	     	    game => 9,
		       ...
		    fielding => {
			p => {
			    tc => 43,
			    pop => 4,
			    ...
			},
			# b1 => { }, b2 => { }, b3 => { },
			# first, second and thrid baseman should be
			# b1, b2, and b3 respectively for convenient in
			# fielding context.  Because the initial of the
			# name of subroutine can't be a number in perl.
		    },
		};
		...
	    }
	},
	Athletics => {
	    ...
	},
    },
 };

TERMS

Available terms of players (including teams and league, which are accumulated from players and could be treated as an abstract player) are:

# pitching
p_game win lose tie gs sv bs hld cg sho ip p_pa np h_allowed
hr_allowed sh_allowed sf_allowed p_bb p_ibb hb p_so wp bk ra er

# batting
pa ab rbi r h 1b 2b 3b hr tb dp sh sf ibb bb hbp so sb cs
tc po a e f_dp ppo tp pb c_cs c_sb

# fielding
pos fgame tc po a e f_dp tp pb c_cs c_sb

And there are additional terms for team:

game win lose tie

FUNCTIONS

new([%hash])

Create sabermetric data set of a group of teams. The following keys are supported:

    league: a string like 'CPBL', which is a module and has to be defined in Baseball::Sabermetrics::League::CPBL.

    data: If your league is not exists there, you can feed in a structure mentioned above.

    Accumulate: If $hash{Accumulate} is false, players data will not be accumulated to their teams and the league (and therefore team-wise and league-wise statistics are not allowed). Default is to accumulate stats.

players([$name])
for ($league->players) { ... }
# or specify the name for the player
print $league->players('Someone')->obp;
teams([$name])
for ($league->teams) { ... }
# or specify the name for the team
print $league->teams('Someone')->win;
pitchers

Return all pitchers, i.e., NP (Number of Pitches) > 0.

batters

Return all batters, i.e., PA (Plate Appearances) > 0.

AUTHOR

Victor Hsieh, <victor at cpan.org>

BUGS

Please report any bugs or feature requests to bug-sabermetrics at rt.cpan.org, or through the web interface at http://rt.cpan.org/NoAuth/ReportBug.html?Queue=BaseBall-Sabermetrics. I will be notified, and then you'll automatically be notified of progress on your bug as I make changes.

SUPPORT

You can find documentation for this module with the perldoc command.

perldoc Baseball::Sabermetrics

You can also look for information at:

COPYRIGHT & LICENSE

Copyright 2006 Victor Hsieh, all rights reserved.

This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself.