My recent games against human players suggest that 14k might be an appropriate rank for me. However, against Billy, I lose badly when the handicap is set accordingly.
Typical example game (Billy as White at 12k, me as Black at 14k, Handicap=2, Billy wins by a margin of 50 points).
Obviously, I make a lot of mistakes, but I also make them against human players, so there must be something that I am not so good at that Billy can exploit relentlessly. If anyone can weigh in why I get beat so badly by a soulless piece of software, I would be interested because this would enable me to work at this particular aspect of my game.
Black lost a lot of ground in the sequence from 18-24, especially the choice to back off rather than cut and take influence.
After that, black failed to attack or put any pressure on white, so Billy was able to play fast and get away with too much. The game became even within 40 moves.
Besides technical stuff like the right pattern for this or that situation, maybe the most important point concerns your attitude towards the game. I want to emphasize fighting spirit. It’s important to know good patterns, but people who just play defensive moves can never get better. I advise you to fight and attack, even against Billy and stronger players. This will mean you lose a lot of games in the short term because attacking is more difficult than defending. But in the long term this is more instructive as you learn a lot facing new moves and variations.