diff --git a/OpenSkillSharp.Tests/Models/Data/plackettluce.json b/OpenSkillSharp.Tests/Models/Data/plackettluce.json
index 2b8d58e..41fe81e 100644
--- a/OpenSkillSharp.Tests/Models/Data/plackettluce.json
+++ b/OpenSkillSharp.Tests/Models/Data/plackettluce.json
@@ -86,21 +86,21 @@
     ],
     "team_2": [
       {
-        "mu": 23.083700519022745,
+        "mu": 20.599656070925114,
         "sigma": 8.222674397835641
       },
       {
-        "mu": 21.717476072569045,
+        "mu": 20.47545384852023,
         "sigma": 8.277466291367071
       }
     ],
     "team_3": [
       {
-        "mu": 21.717476072569045,
+        "mu": 20.47545384852023,
         "sigma": 8.277466291367071
       },
       {
-        "mu": 23.083700519022745,
+        "mu": 20.599656070925114,
         "sigma": 8.222674397835641
       }
     ],
@@ -160,7 +160,7 @@
   "ties": {
     "team_1": [
       {
-        "mu": 23.241111866333558,
+        "mu": 21.63766806988004,
         "sigma": 8.310709773172306
       }
     ],
@@ -176,15 +176,15 @@
     ],
     "team_3": [
       {
-        "mu": 21.479966996534408,
+        "mu": 19.87652320008089,
         "sigma": 8.237522411103104
       },
       {
-        "mu": 21.479966996534408,
+        "mu": 19.87652320008089,
         "sigma": 8.237522411103104
       },
       {
-        "mu": 21.479966996534408,
+        "mu": 19.87652320008089,
         "sigma": 8.237522411103104
       }
     ]
@@ -261,4 +261,4 @@
       }
     ]
   }
-}
\ No newline at end of file
+}
diff --git a/OpenSkillSharp.Tests/Models/PlackettLuceTests.cs b/OpenSkillSharp.Tests/Models/PlackettLuceTests.cs
index 549b03c..b199fa8 100644
--- a/OpenSkillSharp.Tests/Models/PlackettLuceTests.cs
+++ b/OpenSkillSharp.Tests/Models/PlackettLuceTests.cs
@@ -149,4 +149,16 @@ public void Rate_Balance()
         // Assert
         Assertions.RatingResultsEqual(expectedRatings, results);
     }
+
+    [Fact]
+    public void Rate_AllScoresTied()
+    {
+        PlackettLuce model = new PlackettLuce { Mu = 30, Sigma = 30.0 / 3 };
+
+        ITeam[] teams = [new Team { Players = [model.Rating()] }, new Team { Players = [model.Rating()] }];
+        ITeam[] result = model.Rate(teams, scores: [0, 0]).ToArray();
+
+        Assert.Equal(30, result[0].Players.Single().Mu);
+        Assert.Equal(30, result[1].Players.Single().Mu);
+    }
 }
\ No newline at end of file
diff --git a/OpenSkillSharp/Models/PlackettLuce.cs b/OpenSkillSharp/Models/PlackettLuce.cs
index 88e4703..f8358d0 100644
--- a/OpenSkillSharp/Models/PlackettLuce.cs
+++ b/OpenSkillSharp/Models/PlackettLuce.cs
@@ -40,7 +40,7 @@ protected override IEnumerable<ITeam> Compute(
                     return (
                         sumOmega: acc.sumOmega + (
                             iTeamIndex == qTeamIndex
-                                ? 1 - (iMuOverCeOverSumQ / rankOccurrences[qTeamIndex])
+                                ? (1 - iMuOverCeOverSumQ) / rankOccurrences[qTeamIndex]
                                 : -1 * iMuOverCeOverSumQ / rankOccurrences[qTeamIndex]
                         ),
                         sumDelta: acc.sumDelta +
diff --git a/OpenSkillSharp/OpenSkillModelBase.cs b/OpenSkillSharp/OpenSkillModelBase.cs
index 05c8c85..3ef8f0b 100644
--- a/OpenSkillSharp/OpenSkillModelBase.cs
+++ b/OpenSkillSharp/OpenSkillModelBase.cs
@@ -289,6 +289,7 @@ protected IEnumerable<double> CalculateMarginAdjustedMu(
                     double sign = qTeamScore > iTeamScore ? 1D : -1D;
                     return (qTeam.Mu - iTeam.Mu) * (marginFactor - 1) * sign;
                 })
+                .DefaultIfEmpty(0)
                 .Average();
 
             return qTeam.Mu + muAdjustment;