#0 - Jan. 22, 2009, 6:26 p.m.
"Background:
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A persistent player rating system was first hinted at back in TBC as something that might be introduced in WotLK. When I first read about it I was shocked because (as with anyone who played Wc3 competitively) I was aware of how easily the system can be abused, and how it kills competitive PvP.
I sincerely hoped that this was merely an inexperienced member of their team getting a little over-excited with a naïve idea for improving match-making. I sincerely hoped that their development team had the competence to stop this ever going live.
The primary motivation for a persistent rating system was to avoid pairing poorly skilled players against highly skilled players because bad players don't enjoy being stomped. We will later see that this is impossible to achieve since a player's "skill" level is something that that may be projected to anything a player wishes that is below his actual skill level, but we will go into this in detail later.
Anyway, 3.0.8 came along and out-of-the-blue the new and untested system was dumped upon us. What made it even more unsavory to swallow was that it came with major bugs leading to widespread chaos with skyrocketing ratings, prestigious achievements being awarded for mediocre play, and general inconsistency.
However this post is not concerned with these bugs, and in fact these bugs are currently clouding a far more serious issue. The issues I'm trying to highlight exist with any persistent rating system, and they would still exist even if Blizzard had smoothly implemented the system. Even if they had kept the elegant zero-sum scoring system for team ratings and used the persistent (or hidden) rating solely for match-making, the problem would still exist!
The fundamental flaw with a persistent rating system
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Essentially a persistent rating attaches a sense of "state" to a player that persists between arena teams. This "state" affects how the player is to be paired, and therefore affords the player a means by which to manipulate how he is paired. A player will therefore aim to be in the optimal "state" before beginning a competitive team.
Laughably Blizzard have hidden this persistent rating (and gone so far as to call it a "hidden" rating) in the naïve hope that players will not attempt to manipulate that which they cannot see.
A simple way to abuse this system would be to deliberately play badly for many games: It need not require losing every game, even winning 50-50 at a low rating will be enough to establish a low persistent rating. When this low rating is established, the player can then simply begin a new team, start playing well, and reap the benefits of beating players who are now judged (by a flawed system) to be more skillful.
Flawed regardless of the rate of evolution
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A persistent rating attempts to judge a players skill level by looking at his current team or personal rating. This means that the persistent rating must evolve according to actual ratings. For a persistent rating to be meaningful and persistent it must evolve slowly and remain stable. However this makes establishing a false persistent rating more potent, and so the system may be abused to a greater degree.
A fast evolving persistent rating undermines the whole desired purpose of a persistent rating system since a player can easily "reset" his persistent rating by playing poorly: Suppose a gladiator has been playing at 2300+, and wishes to boost a friend to 1800. The gladiator need only quit his team, begin a new team and play badly for however long it takes to decrease his persistent rating before helping his friend out.
Either way the system does not work - whether it evolves quickly or slowly or anywhere in between it will be susceptible to establishing a false persistent rating. Even if the rating were non-decreasing, you would see players deliberately maintaining low ratings (or even rerolling characters!) to establish a convincing low persistent rating so that they could capitalize towards the end of the season.
In fact it's impossible for a persistent rating system to succeed: if it's potent enough to pair low skilled players consistently and award them for occasionally beating more skillful players, then it will be potent enough to be heavily abused. If it is not potent enough to achieve this, then it servers no purpose other than to require a "reset time" for players wishing to help out lower-rated players.
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Stop this folly!
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I play this game for arenas, and the one thing they really had going for them was a solid zero-sum rating system that was stable, elegant, and truly reflectiv
