diff --git a/ChangeLog.md b/ChangeLog.md
--- a/ChangeLog.md
+++ b/ChangeLog.md
@@ -1,5 +1,9 @@
 # Revision history for hanabi-dealer
 
+	## 0.3.0.1 -- 2020-01-12
+
+	* fix bestPossibleRank (and thus isUseless)
+
 	## 0.3.0.0 -- 2020-01-12
 
 	* playable client/server system via WebSocket
diff --git a/Game/Hanabi.hs b/Game/Hanabi.hs
--- a/Game/Hanabi.hs
+++ b/Game/Hanabi.hs
@@ -162,8 +162,8 @@
 
 -- | the best achievable rank for each color.
 bestPossibleRank :: PublicInfo -> Color -> Number
-bestPossibleRank pub iro = toEnum $ length $ dropWhile (==0) $ zipWith subtract (reverse $ numCards (gameSpec pub) iro)
-                                                                                                     (map ((discarded pub IM.!) . cardToInt . C iro) [K5, K4 .. K1])
+bestPossibleRank pub iro = toEnum $ length $ takeWhile (/=0) $ zipWith subtract (numCards (gameSpec pub) iro)
+                                                                                (map ((discarded pub IM.!) . cardToInt . C iro) [K1 .. K5])
 numCards :: GameSpec -> Color -> [Int]
 numCards gs iro = if iro==Multicolor then numMulticolors $ rule gs else [3,2,2,2,1]
 -- | isUseless pi card means either the card is already played or it is above the bestPossibleRank.
diff --git a/hanabi-dealer.cabal b/hanabi-dealer.cabal
--- a/hanabi-dealer.cabal
+++ b/hanabi-dealer.cabal
@@ -10,7 +10,7 @@
 -- PVP summary:      +-+------- breaking API changes
 --                   | | +----- non-breaking API additions
 --                   | | | +--- code changes with no API change
-version:             0.3.0.0
+version:             0.3.0.1
 
 -- A short (one-line) description of the package.
 synopsis:            Hanabi card game