Add imminent "Material Sac" / "hung piece" requirement to Brilliant Move calculations

[Xyvir]

Awhile ago chess.com reworked and simplified it's Brilliancy detector to basically look for two criterion:

1. The move gave the player a material disadvantage by either

   • Moving a piece that will be captured next turn and not capturing a stronger piece with that move OR
   • Not defending a piece that is under attack and will be captured next turn or
   • Revealing a piece to capture next turn that was otherwise safe.

2. The played move (that 'hung' a piece) was the 'best' analysis move by a wide enough margin.

The feels pretty good to me, but the currently lichessTools brilliancy analysis doesn't seem to use the same criteria.

for instance:

I don't know why this was marked as a brilliancy

I kinda feel like this one shoulda been marked a brilliancy; but it wasn't even marked good?

Anyways, just some food for thought.

-Xyvir

https://lichess.org/XhoMkNgX#63

[Siderite]

Thanks for this! I will look into it. For the moment the brilliancy algorithm is pretty weak and I don't have the time to rework it.