Horde AI bug

Thanks for a new variants engine, it is really strong, good work Toadofsky and Ubdip.

However there is a bug -
Stockfish do not move in this game
en.lichess.org/mQ3QgPjsyE7M

The AI always stops moving after 150 moves. However, I don't remember if this is a bug, or something by design.

Yes the limit is by design
github.com/ornicar/lila/commit/47cec5f618c7f34a61af0e39b5c57a29a64cef42

@Nonpareil: Since you are a very strong horde player, it would be great if you could state the most significant (positional) weaknesses of the engine. I think one problem is that it underestimates the value of having a piece behind the pawns, since this information is not used in the evaluation function so far. I have already tried to add a bonus for pieces that break through the pawn wall, but it did not perform well in selfplay.