fix engine ratings

Author: Deltachaos

src/Engines/GarboChess.lua

@@ -2099,19 +2099,24 @@ end
 --------------------------------------------------------------------------------
 
 function M:GetEloRange()
-    return { 1400, 2200 }
+    return { 1100, 2200 }
 end
 
 function M:GetAverageCpuTime(elo)
     -- Estimated CPU time in ms based on ELO (deeper search at higher ELO)
     -- Always faster than sunfish and fruit
     -- Faster than zugzug at depth 4+, slower at depths 1-3
+    local factor = 1
+    if elo >= 1800 then
+        factor = 3
+    end
+
     local range = self:GetEloRange()
     local t = (elo - range[1]) / math.max(1, range[2] - range[1])
     -- At low ELO (depth 1-3): ~200ms (slower than zugzug at depths 1-3)
     -- At high ELO (depth 4+): ~700ms (faster than zugzug at depth 4)
     -- Always faster than sunfish/fruit
-    return 200 + t * 500  -- 200ms to 700ms
+    return 200 + t * 500 * factor  -- 200ms to 700ms
 end
 
 --- Map state.elo to search depth (weaker = shallower, stronger = deeper). Uses state.ply_limit when set.

src/Engines/Sunfish.lua

@@ -804,7 +804,7 @@ end
 -- Engine interface
 --------------------------------------------------------------------------------
 function M:GetEloRange()
-    return {1200, 2000}
+    return {600, 1500}
 end
 
 --- Node limit from state.node_limit when set, else from state.elo.
@@ -828,10 +828,10 @@ function M:GetAverageCpuTime(elo)
     local nodeCount = 500 + t * 3500
     if nodeCount < 2000 then
         -- Below 2000 nodes: sunfish is faster, so lower time
-        return math.floor(250 + t * 250)  -- 250ms to 450ms
+        return math.floor(400 + t * 250)  -- 250ms to 450ms
     else
         -- Above 2000 nodes: fruit is faster, so sunfish time increases more
-        return math.floor(450 + (t - 0.43) * 1300)  -- 450ms to 1300ms
+        return math.floor(600 + (t - 0.43) * 1800)  -- 450ms to 1300ms
     end
 end
 

src/Engines/Zugzug.lua

@@ -29,8 +29,8 @@ function M:GetAverageCpuTime(elo)
     -- depth 1: ~40ms, depth 2: ~150ms, depth 3: ~600ms, depth 4: ~2800ms
     -- At depth 4, zugzug becomes slower than garbochess at equivalent ELO
     if elo <= 400 then return 40 end       -- depth 1 (faster than garbochess)
-    if elo <= 700 then return 150 end      -- depth 2 (faster than garbochess)
-    if elo <= 850 then return 600 end      -- depth 3 (faster than garbochess)
+    if elo <= 700 then return 600 end      -- depth 2 (faster than garbochess)
+    if elo <= 850 then return 800 end      -- depth 3 (faster than garbochess)
     return 2800                            -- depth 4 (slower than garbochess at equivalent ELO)
 end