Shallow depth pruning on NonPV advanced pawn push

[stockfish] / Readme.md

diff --git a/Readme.md b/Readme.md
index be3247639b7e7fa404d20715b0cba3f1e808676d..10ffdeae4ff34736171eed3b5155812d8f443487 100644 (file)
--- a/Readme.md
+++ b/Readme.md
@@ -55,7 +55,16 @@ Currently, Stockfish has the following UCI options:
     Leave at 1 for best performance.
 
   * #### Skill Level
-    Lower the Skill Level in order to make Stockfish play weaker.
+    Lower the Skill Level in order to make Stockfish play weaker (see also UCI_LimitStrength).
+    Internally, MultiPV is enabled, and with a certain probability depending on the Skill Level a
+    weaker move will be played.
+
+  * #### UCI_LimitStrength
+    Enable weaker play aiming for an Elo rating as set by UCI_Elo. This option overrides Skill Level.
+
+  * #### UCI_Elo
+    If enabled by UCI_LimitStrength, aim for an engine strength of the given Elo.
+    This Elo rating has been calibrated at a time control of 60s+0.6s and anchored to CCRL 40/4.
 
   * #### Move Overhead
     Assume a time delay of x ms due to network and GUI overheads. This is useful to