After several tries trying to find an Elo level that could serve for calibraiton on the Mephisto Phoenix , I decided to give it another try. Untill now The Chessmind Fisher personality at 1800 elo , which means the engine searched 9 ply deep and provides 10 moves (10 mulit Pv, successively beath the elo levels 2000, 2100, 2200 for Stockfisch on the Mephisto Phoenix in 15 minute games. But there is some uncertainty as to whether these elo levels include errors or randomness on purpose. which does apparently not work so well vs the Chessmind plan- based GM style system even at limited depth . Then i tried the 2200 Hiarcs elo level but here too the Chessmind Fischer 1800 personality , with some dificulty though, eventually prevailed.

So i decided to switch strategy , and have the opponent level set to Hiarcs fixed depth 9, no elo limit no time limit.

Since Chessmind Fischer at 1800 elo is also limited to 9 ply fixed depth , at least we should not be unsure whether the UCI limit strength or other hardcoded randomness should intervene in the play. So hiarcs could calculate everything untill ply 9 and then make a move, which sometimes took 2 minutes or more .

Unfortunately we could not finish the whole game since a the same time i discovered a bug in the clock in the Play mode: The time kept running even after Hiarcs made a move ! But by that time .... the position was crushing again for the Fischer 1800 elo Chessmind Personality .

There was a wild 27 ...b5 (!?) move by Chessmind Fisher, giving away a pawn, but at the same time making sure (i think) that the black pawn chain in the Q Side could no longer be attacked.
I am unsure on how to interpet this all and will keep on testing.