The results against strong humans were very impressive today. And there are a few more weaknesses in the endgame to be patched too.
These changes came about, because I have been proposing to fit the evaluator from my ancient Chu 2.11 program to HaChu. This evaluator meant that Chu 2.11 played really beautiful opening play (in comparison to HaChu 0.18, or Zillions of Games – not compared to a human!). But it’s search was quite weak. So the prospect of combing my evaluator with HaChu’s search engine looked interesting.
So this week HGM began explaining to me how HaChu worked, and I showed him my evaluator. We began discussing my piece tables (which were carefully designed to enable reasonable opening play without the step movers getting in the way of the ranging pieces, and vice versa.). From these discussions, HGM tried some of the principles out in HaChu 0.19, and the effect was surprisingly (to me) large.
With further relatively easy improvements to come, I wonder how much (if any) of an improvement implementing my piece tables will make. The only way to find out is to try, and currently I’m planning to have a go after Easter.
One interesting point about these changes – HGM tells me that HaChu 0.19 loses to HaChu 0.18.