We have 15 players who have a clearly defined rating. Their sum is the criterion, i.e., 10*60+5*20=700, which is clear. Next, you adjust the final sum by an amount equal to the number of players with a formed rating multiplied by the average beginner's rating... Why? The essence of this adjustment is not intuitively clear...
∑(Ri)+20(or 30)*n(a)
. I repeat, physically it is almost the same thing. If this is simpler and more visual, let it be so; from now on in all discussions we will calculate using this, only specifying the beginner's rating . After all, the main idea is clear: each participant increases (linearly, but not significantly) the tournament coefficient.