Always a touchy subject…
Currently, WN8 is the rating system used for both the players’ overall statistics, as well as the battle rating. There is, however, a problem with WN8. It does not take into effect spotting damage, and due to the way it’s calculated, some tanks can receive insane values when they’re doing “better” than expected. For example you can easily pull 10.000 WN8 off a 59-16 match if you’ve actually taken the time to do a lot of direct damage; which isn’t exactly what that tank is known for.
Spotting damage is a fickle thing,because it relies on first you lighting up (or tracking) a tank, and then your teammates doing damage to it. As such, assisted damage isn’t something you can predict with any degree of success, but it does have a distinct influence on a match.
Currently WN8 rewards suicide scouters to a certain extent when they spot 10 tanks; yet the scout that plays the waiting game and perhaps comes in after the suicide scout, but keeps targets lit so they can be appropriately smashed to bits by the team doesn’t get much of anything for it as far as the rating value goes. The reason for that is simple: WN8 really was designed to work off dossiers and API data to give a global indication of what someone’s potentially capable of doing. Whether it’s accurate or not is something that remains, as always, a touchy subject.
But on that note, given that a replay does contain things like you lit a tank up, and another player damaged it kind of data. Or tracking, it’s the same thing. You did something that your team capitalized on. That may not be entirely relevant to your rating, but could be used as a modifier value. After all, if you light things up on the far side of the map where nobody’s around, you’re not doing a proper scouting job, really, right?
There is more data like that in replay files, and it’s made me consider an attempt to come up with my “own” rating formula which will take into account things like mentioned earlier, to hopefully end up at a somewhat more representative value as far as a rating goes. But it may take a while since I’m bad@math and bad@statisticalanalysisesses. I’ve considered modifying WN8 to take into account assisted damage (e.g. damage done by your team as a result of you spotting or tracking something), but that can’t really be qualified as true damage – and if it was, you’d still end up with stupendously high numbers since there’s no expected value for assisted damage available.
At any rate, there’ll be some changes coming eventually to battle ratings.