Rating system for online games in Heroes of Might and Magic IV.

Rating Calculation System:
En - new rating, Eo - current rating, 10 - coefficient, Gw - wins, Gl - losses. En = Eo + 10(Gw - Gl).

In my opinion, this formula is not suitable. At first glance, it seems that everything will work well because, for one tournament, the formula calculates the rating correctly. But what if we predict different situations across several tournaments? For example, in the first tournament, there were 5 participants. There was a strong player A, but not player B. Player A won 4 games (if there were 100 people, he might have won all 100 games :). In the second tournament, there were 10 people. But player A did not participate, but there was a strong player B (as strong as A). Player B won 9 games in the second tournament. As a result, player B will have a higher rating than player A, which shows that the rating will be directly proportional to the number of wins in the played tournaments. But was player A to blame that the organizers only found 5 people for the first tournament? However, in this case, it turns out that having one tournament each and taking first place in that tournament, players A and B have different ratings. It seems logical that there were more people in the second tournament, but I repeat, is player A to blame that there were not that many people there? In the form you are currently proposing, it is not much different from the rating that Adelaide proposes. Well, I'm not against it :) Try it if you don't mind.
PS. Optimal, I'll send you what I promised via email. Take a look at it when you have time.
In that game, the system was applied to matches (consider it a tournament), and no more than 11 people could participate. Therefore, I don't understand what will happen if 20 people suddenly participate in a tournament, and how that system will behave in that case. And also, there is a number in the formulas that is unclear where it comes from. It is probably somehow related to the number 11.