I'm surprised to be making this post, because I've never seen TSH make
incorrect ratings calculations, but I'm not sure if the ratings
calculations presented by TSH at the Mississauga Open this weekend are
entirely accurate. I'm posting this to CGP in case others want to
check their calculations from the weekend, and to TSH-users in case
there's a bug that needs to be fixed, or some sort of documentation
needed to ensure that other directors have TSH set up correctly to do
the proper calculation. Of course, if I've made a mistake as well, I
fully expect that someone will correct me. Please let me know.

http://shellstevens.com/moo/A-ratings-016.html is the URL to the final
standings of the MOO.

As an example, I'm going to go through and calculate my rating change
manually. I will be verbose in my calculations for the benefit of
those not entirely familiar with the ratings system.

Initial rating: 1331
Opponent 1: 1717 (ratings difference -386, win expectation 0.086)
2: 1656 (-325, 0.125)
3: 1458 (-127, 0.327)
4: 1890 (-559, 0.024)
5: 1567 (-236, 0.202)
6: 1805 (-474, 0.047)
7: 1217 (+114, 0.657)
8: 1412 (-81, 0.387)
9: 1210 (+121, 0.666)
10: 1596 (-265, 0.174)
11: 1466 (-135, 0.317)
12: 1519 (-188, 0.253)
13: 1251 (+80, 0.611)
14: 1431 (-100, 0.362)
15: 1670 (-339, 0.115)
16: 1805 (-474, 0.047)

Total win expectation: 4.400
Number of wins: 10.0
Over expectation: 5.600
Ratings multiplier: 20
Base increase: 112 points
Acceleration bonus for a gain exceeding 5 points / round: equal to
amount of gain greater than 5 points / round, which is 112 - (16 * 5)
= 32 points
Ratings increase, including bonus: 144 points.
Feedback points: Opponent 9 gained 94 "base" points over the weekend
(garnering 14 bonus points) and Opponent 13 gained 84 "base" points (4
bonus). As each opponent that played the player getting bonus points
gets 0.05 feedback points for each bonus point earned, I should get
((14 + 4) * 0.05) = 0.9 feedback points.
Total ratings increase: 144.9 points, rounded up to 145

New rating: 1476

It appears as if the ratings calculator used at the MOO did not take
the bonus points into account when making the calculations.

--
Andy Saunders
andy@...