playBunny: when you have less games played your bkr will rise or drop more steeply
it takes quite some games to become a bit stable ... the 25 games which are needed to get an established rating isnt really enough ...
you can see that mjost clearly when playing opponents with roughly the same rating ... you will both win or gain the same amount of rating ... but this will be slightly more for a player who has played less games.
when i was around 100 game i think it was 13 points for me, now its around 6 points i think
(your +2 and -13 have an average change of 7 (absolute) .. your opponents -3 and +23 have an avera change of 13 .. this is probably due to the number of games played for each opponent