Well, there already exists a betzaNewer.js, which currently is only used by the Tenjiku Shogi Diagram that plays with modern rules. (And finished second in the yearly Tenjiku Shogi Correspondence Championship, even above Jocly!) This does a limited form of check detection in horizon nodes: it generates moves of the piece that just moved to see if any of these hit the King. And if it detects a check it gives half a ply extension. So it doesn't recognize discovered checks. But human players err on that more often too, so this only makes it play more human-like.
For Modern Tenjiku Shogi, where the first move typically is a mate-in-1 threat, and the second move a mate-in-2 threat (neither through a discovered check) it was very important to have earlier checkmate recognition, or it would not last more than 4 moves with gote. As it was playing without book. (Jocly solves this by having these lines in book.) I think I also put a 'singular-evasion extension' extension in there, which extends a full ply instead of half a ply when only a single check evasion is legal. (Which is the case in the mate-in-2 threat.) This makes the recognition of mate threats more on par with that of material losses.
I suppose I could try to add the drops in there; the check extension would also be very useful for better tsume recognition. (But I would then first have to port all recent improvements in betzaNew.js to it.) If drops are added to the list of legal moves, these would automatically be highlighted. Not sure I can do this any time soon, though.
Well, there already exists a betzaNewer.js, which currently is only used by the Tenjiku Shogi Diagram that plays with modern rules. (And finished second in the yearly Tenjiku Shogi Correspondence Championship, even above Jocly!) This does a limited form of check detection in horizon nodes: it generates moves of the piece that just moved to see if any of these hit the King. And if it detects a check it gives half a ply extension. So it doesn't recognize discovered checks. But human players err on that more often too, so this only makes it play more human-like.
For Modern Tenjiku Shogi, where the first move typically is a mate-in-1 threat, and the second move a mate-in-2 threat (neither through a discovered check) it was very important to have earlier checkmate recognition, or it would not last more than 4 moves with gote. As it was playing without book. (Jocly solves this by having these lines in book.) I think I also put a 'singular-evasion extension' extension in there, which extends a full ply instead of half a ply when only a single check evasion is legal. (Which is the case in the mate-in-2 threat.) This makes the recognition of mate threats more on par with that of material losses.
I suppose I could try to add the drops in there; the check extension would also be very useful for better tsume recognition. (But I would then first have to port all recent improvements in betzaNew.js to it.) If drops are added to the list of legal moves, these would automatically be highlighted. Not sure I can do this any time soon, though.