Tune speculative pruning margins

Based on ~115k games with the auto tuner. Causes _massive_ pruning
compared to original values. Apparently this is still better than the
inevtibale misses that this induces in the search.

engine/src/opts.rs

@@ -23,46 +23,46 @@ pub struct Opts {
     pub threads: usize,
 
     // Time control options:
-    #[uci(default = "40", kind = "spin", min = "1", max = "100")]
+    #[uci(kind = "spin", min = "1", max = "100", default = "40")]
     pub tc_default_moves_to_go: usize,
-    #[uci(default = "95", kind = "spin", min = "1", max = "100")]
+    #[uci(kind = "spin", min = "1", max = "100", default = "95")]
     pub tc_time_buffer_percentage: usize,
-    #[uci(default = "25", kind = "spin", min = "0", max = "1000")]
+    #[uci(kind = "spin", min = "0", max = "1000", default = "25")]
     pub tc_min_search_time_ms: usize,
 
     // Search speculation options:
     //
     /// Futility margin max depth.
-    #[uci(default = "5", kind = "spin", min = "1", max = "5")]
+    #[uci(kind = "spin", min = "1", max = "5", default = "5")]
     pub futility_margin_max_depth: Depth,
     /// Futility margin base in centipawns.
-    #[uci(default = "250", kind = "spin", min = "100", max = "1000")]
+    #[uci(kind = "spin", min = "0", max = "1000", default = "17")]
     pub futility_margin_base: Value,
     /// Futility margin per-depth in centipawns.
-    #[uci(default = "300", kind = "spin", min = "50", max = "1000")]
+    #[uci(kind = "spin", min = "0", max = "1000", default = "100")]
     pub futility_margin_per_depth: Value,
     /// Razor margin base in centipawns.
-    #[uci(default = "450", kind = "spin", min = "100", max = "1000")]
+    #[uci(kind = "spin", min = "0", max = "1000", default = "323")]
     pub razor_margin_base: Value,
     /// Razor margin per-depth in centipawns.
-    #[uci(default = "300", kind = "spin", min = "50", max = "1000")]
+    #[uci(kind = "spin", min = "0", max = "1000", default = "249")]
     pub razor_margin_per_depth: Value,
     /// Delta pruning margin in centipawns.
-    #[uci(default = "250", kind = "spin", min = "0", max = "1000")]
+    #[uci(kind = "spin", min = "0", max = "1000", default = "12")]
     pub delta_margin: Value,
     /// Internal iterative deepening depth reduction.
-    #[uci(default = "2", kind = "spin", min = "1", max = "5")]
+    #[uci(kind = "spin", min = "1", max = "5", default = "2")]
     pub iid_depth_reduction: Depth,
     /// Internal iterative deepening lower depth limit.
-    #[uci(default = "5", kind = "spin", min = "5", max = "10")]
+    #[uci(kind = "spin", min = "5", max = "10", default = "5")]
     pub iid_depth_lower_bound: Depth,
 
     // Move ordering options:
     //
     /// How many centipawns bonus to give to moves that are the most frequent in history stats.
     /// Other moves will be given a bonus scaled linearly on how frequent they are compared to the
     /// most frequent move square.
-    #[uci(default = "10", kind = "spin", min = "0", max = "100")]
+    #[uci(kind = "spin", min = "0", max = "100", default = "10")]
     pub max_history_stats_impact: usize,
 }