Thai Makruk

What a coincidence. I was just analyzing some Makruk end-games, to see if it would be possible to enhance Fairy-Max' play with the aid of a "poor-man's tablebase", which just contains a number of critical positions and their distance to mate. These positions are then loaded in the hash table before the game, so that they will be probed during search.

Especially the end-game King + Silver General + Ferz vs bare King is pretty hard. I guess that was to be expected, as you are barely above the draw threshold here. Two Ferz is a draw (there is a handful mate-in-2 positions, but that is all), and Silver has only a single move more than a Ferz. Yet that is enough to make it a general win. The forward-backward asymmetry of the Silver and the color binding of the Ferz make all corner different. It seems that the worst case is mated-in-57.

Funny enough it seems that only allowing mate in the most favorable corner (or taking any mate-in-1 the opponent is stupid enough to expose himself to) makes it winnable in 58 moves. That you don't want to use the other corners is hardly a handicap. (Not using the mate-in-1s, though, drove up the length to 92 moves!) Perhaps this makes it possible to put the PV of that mate-in-58 in the book, and hope that the distance of all other positions to this PV is small enough that the search can find it.

I never looked at how the Bonanza engine really worked. I only looked at the protocol driver, to replace WB-protocol commands by the corresponding Bonanza commands in a pre-processor routine.

Exactly. There already was a way to do that, with tandem adapters b2u (Bonanza to UCI) and UCI2WB, but the Bonanza protocol only accepted time is integer seconds, which was not precise enough for the bullet games I usually play for testing.

BTW, why are you bothering with bitboards? I don't think they can be competitive at all when the board doesn't fit in a single machine word.

The endings  in Thai chess , makruk  are like  western chess.The  more difficult is with  his bishop  KHON and MET (queen)  , you need to push his king to  his corner to check mate with KHON.

The end game of Thai Chess it different from Chess. A lot because constant values of pieces can change some time Cone more than Ma (Knights) and Med (Biangai) change Value = Cone it will make Knight of opposite position can capture pieces enough to fine check mate at the end game. But If you can Telll your program. if 1 med or two med it mean draw. if one cone (Bishop) it mean draw. if 1 knight it mean draw if 2 knight it mean draw game. if 1 king it mean draw. if any pawn the same squre it mean draw. if med the same square it mean draw game. It will make you program no skill of draw game and make Maemai Makruk thai more than 500 Maemai. it not include many position on board at the end games that much a lot of maybe 10000 million position. if you can tell your programs I mean fairy-max it will clever program. I hope you understand that I mean and one other thing Med it only have 1 pieces on board. When promotion it should be another pictures it call Biangai but moves like Med. And the rules of thai chess at the End game it different. Sakkadan and Sakmak. if you do only Sakkadan. it Call open Makruk not the real Makruk Thai. if you can improve it. It will perfect program. I hope you can do it. Wait to see. Thank you.

A hard  ending  , fish and horse,(queen and knight)  50 moves to mate king . https://www.youtube.com/watch?v=oCBK5mDLuXk

Makruk has several variants. For example: Makpong, Ouk Chatrang, Asean Chess...