Player rating for tournaments across all installments of Heroes.

Let me clarify a small point regarding aging. It's the current rating that ages, not the annual one. Is the annual rating simply the sum of current ratings? If so, then the annual rating also ages. Wouldn't it be simpler to make it so that the rating doesn't age, but is reset each year? And the player's profile (or the final table) would display the previous year's result.

I don't even know what the Annual Rating is. I can say this about my own:
1. There's a player who hasn't played anywhere yet - their rating is 0.
2. The player plays in a tournament. Now they have a rating that they earned from the tournament, Rtournament.
3. The player plays in another tournament. Now Rtournament becomes Rold. And for this tournament, they earn Rtournament again.
4. Now the player has a new rating, Rnew, which is calculated by adding 2/3*Rold and Rtournament.
Rnew = 2/3*Rold + Rtournament

2/3 - This is the aging factor. The aging factor could also be 1/10.

5. The player goes to a tournament to earn Rtournament again. After the tournament, Rnew is now called Rold, and now go to step 4 (cycle).

Added 4 minutes later

1. We calculate the tournament rating using a complex formula.
2. The sum of tournament ratings for the year (without aging) is the annual rating.
3. The sum of tournament ratings (with aging applied) without being tied to time is the current rating... The aging procedure, applied constantly, negates old results, and therefore, in the end, the current rating only reflects the latest achievements in descending order...

I don't understand what you mean by "in descending order"? The Current Rating can both increase and decrease, but if the player is constantly winning and gaining points, there is a ceiling, so there's no point in resetting it. It can also decrease on its own. I'm saying this to AlexPank.