The script ./pgnrate.tcl invokes the BayesElo software with a PGN file to
produce a rating for players included in the PGN file. To compile the BayesElo
software, run 'make' in the ../BayesElo/ directory.

Usage: ./pgnrate.tcl <pgn_file> [-anchor <player>] [-elo <elo>]
       where the -anchor and -elo are optional.

When given a PGN file, the script produces output that looks like the following:

  anchor: nobody
     elo: 300

Rank Name         Elo    +    - games score oppo. draws 
   1 depth6        39   28   28   400   58%   -10   56% 
   2 hattack250     1   28   28   400   50%     0   56% 
   3 hattack500    -8   29   29   400   48%     2   54% 
   4 depth5        -9   29   29   400   48%     2   53% 
   5 hattack750   -23   29   29   400   45%     6   52% 

This means the PGN file contained games played between 5 players: depth5,
hattach250, hattach500, depth5, and hattach750. The 'Elo' column shows their
respective ratings (higher the better), and '+' and '-' columns show the error
margin, which shows the confidence level. There are total of 1000 games played
and recorded in this PGN file, where each player is involved in 400 games. The
'score' column shows the percentage of (# of wins / # of wins + losses). The
'draw' column shows the percentage of draws. We are unclear what the 'oppo.'
column is for, but a guess is the average Elo score of its opponents.

The -anchor and -elo options are used to defined an "offset," which sets the
rating of one of the players to be certain score. For example, the invocation of

./pgnrate.tcl <pgn_file> -anchor depth6 -elo 100

will show the ratings calculated by offsetting the player depth6's rating so
that it's 100, which results in:

  anchor: depth6
     elo: 100

Rank Name         Elo    +    - games score oppo. draws 
   1 depth6       100   28   28   400   58%    52   56% 
   2 hattack250    63   28   28   400   50%    61   56% 
   3 hattack500    53   29   29   400   48%    63   54% 
   4 depth5        53   29   29   400   48%    64   53% 
   5 hattack750    38   29   29   400   45%    67   52% 


If the -anchor option is not used, no offset will be used. If the -anchor option
is specified but not the -elo, a default of -elo 300 is used.
