I've implemented Jon Dart's suggested changes and I think they bring some improvement to playing strength. However to be honest, I'm not sure. My small tests so far point in all kinds of directions.
I need to set up a new testing environment and have taken a look at cutechess-cli which seems really nice. But I'm having problems with Mediocre crashing (or rather stalling) while running tournaments. Especially the new version. It also leaves really expensive Mediocre processes running, completely clogging up the computer.
I have no idea why.
This brings me to an important point that's been missing in Mediocre since the beginning. A decent logging framework. This should shed some light on those pesky stalls.
So a TODO for the next couple of days:
Set up a testing environment using cutechess-cli, some creative scripting (to be able to run gauntlet matchs) and a number of well-chosen engines. Most likely using the YATS testing again (even though I can't get ProDeo to work anymore).
Get some decent logging going. This should help immensely in tracking down bugs and getting a feel for where improvements might be needed.
Apart from Jon Dart's improvements:
Pondering - It's time to get it done, and shouldn't take too long.
Endgame knowledge and evaluation - Take a look at what I started with two years ago. I might be able to shake out some improvements.