From: Larry Kaufman <lkaufman <at> WIZARD <dot> NET>
Date: 11 apr 1997
Subject: US Shogi Rating System (corrected copy)

        US Shogi Rating System=20

        by Larry Kaufman,=20
        Ratings Committee Chairman

        Although the DC Shogi club rating system has been running smoothly
for a number of years and has worked very well, we have decided to make some
revisions in preparation for making the system into a national rating system
for the U.S.
        For one thing, in handicap games the odds-giver has been winning too
heavily at certain handicaps, so these handicap values are being reduced.
Also, even though our Dan ranks align well with the rest of the world, our
numerical ratings for the stronger players were a bit high compared to the
numerical ratings of both Europe and the Japan Amateur Shogi Renmei.
Therefore, we are taking a major step to correct this problem.
        Finally, we are making it easier for novice players to gain points
in order to avoid the necessity for arbitrary re-ranking rapidly improving
players.  However, the rating committee still will reserve the right to
re-rate a player to his current rank in cases where his rating is clearly=
 not
representative of his current strength; this often happens with rapidly
improving players who mostly play unrated games.
        The most drastic change we are making is to reduce the width of the
1kyu rank to 100 points, the same as the other kyu ranks.  This in turn=
 means
that the starting rating for each dan rank is being reduced by 100 points.
        In order not to change anyone's rank, ratings are being adjusted as
follows: all players rated over 1600 are being debited by 100 points; all
players between 1400 and 1600 are being debited by half the excess over
1400; players under 1400 remain unchanged.  Players rated 2200 or more will
now be on the 2%/8 point scale; players rated 2000-2199 will be on the 3%/12
point scale, and we are introducing a new bracket for players under 1400 at
5%/20. Players under 1200 who gain points in any tournament will have their
gain doubled.
        In all cases where a player passes a threshold as a result of an
event, his gain or loss is adjusted to reflect the formula in effect on the
other side of the threshold.  Example: a player rated 1100 gains 60 points
in a tourney, which is doubled to 120.  Since that puts him over 1200, he is=
 not
entitled to any bonus points beyond 1200, so his new rating is exactly 1200,
not 1220.  Second example: a player rated 2220 loses 30 points on the 2%/8
point scale.  Since he should be at 3%/12 once under 2200, his loss below
2200 is increased by 50% from 10 to 15 points, so his new rating is 2185,
not 2190.
        For those not familiar with our system, players are initially
assigned a numerical rating based on their rank, as best we can estimate it
from information they supply about results against ranked players.  Each
rank has a rating range associated with it; players are normally started at=
 the
middle of their rank, although if they are between ranks they may be started
at the bottom of the higher rank.  The rank for a novice is arbitrarily set
at 15 kyu, with a rating range of 1-99 and a starting point of 50.  14 kyu
is then 100-199 (starting point 150), 13 kyu 200-299 etc. all the way to
1kyu, which is 1400-1499 (starting point 1450).
        Then come the dan ranks, which are 200 points wide.  So Shodan (1st
Dan) is 1500-1699 (starting point 1600), 2 dan is 1700-1899 (starting point
1800) etc. up to 6 dan which is 2500-2699 (starting point 2600).  So far we
have never had a player rated in the six dan range, but one Japanese player
who was in the Shoreikai (training to become pro) as a child did come rather
close.  Note that being rated within the range for a rank does not entitle a
player to claim that rank.  Currently, we award the rank permanently only
when the player has remained within the required range for 20 consecutive
rated games.
        When players play even (Hirate) games in tournaments or clubs, they
are normally rated by adding 4% of the rating difference to the lower rated
player, subtracting 4% from the higher rated player, adding 16 points to the
winner's rating, and subtracting 16 points from the loser's rating.  As
explained above, these coefficients are modified for players 2000 and over
and for players under 1400.  If the rating difference exceeds 350, the game
may not be rated unless it is a tournament game, in which case the number
350 is used as the rating difference regardless of the real difference.
        No game may be rated at a time limit faster than 20 minutes plus 30
seconds byoyomi or 40 minutes without byoyomi per side (10 minutes with 30
seconds delay or increment per move is also acceptable).  All of the rating
changes for a player in a tournament are summed before the new rating is
calculated, so the order in which the games were played makes no difference.
Draws are not rated.
        As for handicap play, the rating calculation is the same as for an
even game, except that the handicap value (see below) is added to the
receiver's rating before calculating the rating difference.
        We have a guideline of recommended handicaps which we follow in our
tournaments, but in club games players are at liberty to play rated games at
any handicap so long as the adjusted rating difference is less than 350.
The new handicap values are as follows: Sente (1st move) 25, Lance (left)
50, Bishop 250, Rook 300, Rook & Lance (left) 400, Rook & Bishop 600, 3
piece (odds-giver chooses the lance) 650, 4 piece 750, 5 piece (right
knight) 900, 5 piece (left knight) 1050, 6 piece 1200.  Three piece is no
longer a recommended handicap but is still ratable.  Handicaps of 7 and 8
pieces are not ratable but for purposes of estimating ratings of novices may
be valued at 1600 and 2000 respectively.
        The recommended ranges for handicaps are: difference of 0-24 even,
25-99 Sente (1st move), 100-199 Lance, 200-299 Bishop, 300-399 Rook, 400-599
R&L, 600-749 R&B (Two Piece), 750-899 4p, 900-1049 5pR, 1050-1199 5pL, 1200
and above 6p.
        Note that when the recommended guidelines are followed the stronger
player will always still be favored to win, except in the range 200-249.  We
felt that bishop handicap was the most appropriate in this range, both
because of the wide gap between lance and bishop and because this important
handicap would otherwise not be seen often enough.  It is to be expected
that if the recommended handicaps are employed, bishop handicap games should
produce about even results, while the other handicaps should still favor the
odds-giver on average by about a 3-2 ratio.
        Certain parallels with chess Elo ratings may come to mind.  On the
USCF scale, 1500 has traditionally been considered the average rating of all
tournament players, though the exact figure varies.  Similarly, the average
rank of club players (at clubs with majority Japanese membership) is
probably between 1 kyu and 1 dan, and 1500 is our dividing line between
these ranks.
        The ratings of the two greatest World Chess Champions of modern
times were both around 2800 at peak.  Of course we don't have ratings for
the Shogi
Meijin, since our system is only employed for amateurs at present.  However,
I believe that the average 5 dan (2400 on our scale) would lose a majority
of games with the Meijin at Rook handicap, were the Meijin playing all-out
to win, and would only be favored at Rook & Lance.  This would imply a
rating of perhaps 2750 for the Meijin.
        Finally, both the USCF scales and our Shogi scale place beginners in
the 1-100 range, so it seems that at both ends and the middle the chess and
Shogi scales are similar.  As for comparing our system with the European and
Japan Amateur Renmei systems, all three start 3 dan players at about 2000
(2020 for Europe), and it is our feeling that at this level the ranks are
fairly similar world-wide.
=09
        Some Examples of ratings calculations:
1) A player rated 1800 beats a player rated 2300 at Rook & Lance.  The
adjusted difference is 100 (2300 -(1800+400)).  He gains 4% of 100 for
playing up, and 16 for winning, for a total gain of 20.  The loser, being
over 2200, is on the 2%/8 scale, so he loses 2% of 100 for playing down, and
8 for losing the game, for a net loss of 10.
2) A player rated 800 loses at 6 piece to a player rated 2400. The adjusted
difference is 400 (2400-(1200+800)).  This being over 350, it is
automatically lowered to 350 (note that this game would not be ratable
unless played in a tournament).  The novice is on the 5%/20 scale, so he
gains 5% of 350 (17.5) for playing up, but loses 20 for the loss, for a net
loss of 2.5 points.  (Note that fractional rating points are accumulated for
all the players games of the tourney, with the final rating of the tourney
then being rounded to the nearest integer).  The 5 dan loses 2% of 350 (7
points) for playing down, yet gains 8 points for the win, resulting in a net
gain of one point.
------------------------------------------------------------------
        The US Shogi Rating System

Rating Correspondences:
Rank    Japanese        Rating
6 Dan   (Roku-Dan)      2500 +
5 Dan   (Go-Dan)        2300-2499
4 Dan   (Yo-Dan)        2100-2299
3 Dan   (San-Dan)       1900-2099
2 Dan   (Ni-Dan)        1700-1899
1 Dan   (Shodan)        1500-1699
1 Kyu   (Ik-Kyu)        1400-1499
2 Kyu   (Ni-Kyu)        1300-1399
3 Kyu   (San-Kyu)       1200-1299=09
4 Kyu   (Yon-Kyu)       1100-1199
5 Kyu   (Go-Kyu)        1000-1099
6 Kyu to 14 Kyu, 100 points for each rank.
15 Kyu  (JuGo-Kyu)      0001-0099

Handicap Guidelines:
Handicap Given        Japanese [Ochi]   Handicap Value    Points Apart
        Even/No Hdcp. [Hirate]                  0              0-  24
s       1st Move      [Sente]                  25             25-  99
L       Lance (left)  [Kyosha]                 50            100- 199
B       Bishop        [Kaku]                  250            200- 299
R       Rook          [Hissha]                300            300- 399
R+L     Rook+Lance    [Hissha-Kyo]            400            400- 599
2p      2 Piece       [Ni-Mai]                600            600- 749
4p      4 Piece       [Yon-Mai]               750            750- 899
5pR     5 Piece Right [Go-Mai, migi kei]      900            900-1049
5pL     5 Piece Left  [Go-Mai, hidari kei]   1050           1050-1199
6p      6 Piece       [Roku-Mai]             1200           1200-1549

1) Lower rated players may decline handicap or accept a lower handicap.
However, games more than 350 points apart will not be rated except in
tournaments.=20
2) Games played at handicaps greater than 6 pieces are not ratable.
3) Unofficially, 1600-1999 is a 7 Piece and >2000 is an 8 Piece Handicap.
4) While not recommended, the value for 3-piece (odd-giver's choice of right
or left Lance) is valued at 650 points.

Rating Formula:
Player Rating:          Rating Formula used:
>=3D   2200      ...      R=3D OR =B1  8 =B1[(RD - HV) x .02]
2000-2199      ...      R=3D OR =B1 12 =B1[(RD - HV) x .03]
1400-1999      ...      R=3D OR =B1 16 =B1[(RD - HV) x .04]
<    1400      ...      R=3D OR =B1 20 =B1[(RD - HV) x .05]

Explanation:
R  =3D New Rating.
OR =3D Old Rating.
RD =3D Rating Difference.
HV =3D Handicap Value (see table above).
=B1  =3D Plus or minus. The winning player adds 8, 12, 16 or 20 points while=
 the
losing player subtracts 8, 12, 16, or 20 points, in accordance with their
rating. The higher rated player will MINUS the resulting number after _the
second_ "=B1" sign in the formula because theoretically he is still=
 considered
the favorite. The lower rated player will ADD this number.
Note: It rarely happens, but if RD is lower than HV then the player giving
the handicap will indeed ADD the resulting number.

Detailed example: A 2100 player beats a 1450 at 2 Piece (600 pt.) handicap
in a club game.
Each player's rating is computed separately.
Step 1. R=3D 2100[OR] + (won) 12 (rating is in the 2000-2199 range)
Step 2. [(650 - 600)=3D 50 x .03 =3D 1.5] Rounded up to 2. (In a tournament,=
 the
fraction would not be rounded, as only the final rating is rounded).
Step 3. R=3D 2112 - (because RD is higher that HV) 2 =3D 2110.
Step 4. R=3D 1450[OR] - (lost) 16 (rating is in the 1400-1999 range)=20
Step 5. [(650 - 600)=3D 50 x .04 =3D 2].
Step 6. R=3D 1434 + (because RD is higher that HV) 2 =3D 1436=20
If, in the above example, the 1450 rated player wins, the results are as
follows: 2100 - 12 - 2 =3D 2086 and 1450 + 16 + 2 =3D 1468.

Bonus: Players rated under 1200 who gain points in any tournament will
receive bonus points by having their gain doubled, unless the doubling
pushes the rating past 1200, in which case 1200 is the new rating.=20

Promotion Requirements: A player must remain rated in the higher rank for 20
consecutive games.

Tournaments: Tournaments may be rated using another method which produces
the same result as the above formula but is a bit faster to use. A complete
explanation of the US Shogi Rating System is available, from the DC Shogi
Club, upon request. Comments and/or suggestions are welcome.

For more information about the DC Shogi Club please contact:
George Fernandez        (703)521-5107   E-mail: fernandz <at> erols <dot> com=20
Larry Kaufman           (301)309-0904   E-mail: lkaufman <at> wizard <dot> net
or Jiro Yoshinari       (202)638-7550 or (800)933-3854
        ***** OUR NEW MAILING ADDRESS *****
DC Shogi Club, c/o Larry Kaufman, 9213 Wooden Bridge Road, Potomac, MD 20854


George I. Fernandez
2000 S. Eads St., Apt. #504
Arlington, VA 22202 USA
Telephone: Home(703)521-5107
           Work(703)451-0300
E-Mail: fernandz <at> erols <dot> com                      =09



Larry Kaufman, 301-309-0904, 9213 Wooden Bridge Road, Potomac, Md. 20854