diff --git a/app/src/androidTest/java/net/pokeranalytics/android/ExampleInstrumentedUnitTest.kt b/app/src/androidTest/java/net/pokeranalytics/android/ExampleInstrumentedUnitTest.kt
index f81f2a2e..4ecd4d71 100644
--- a/app/src/androidTest/java/net/pokeranalytics/android/ExampleInstrumentedUnitTest.kt
+++ b/app/src/androidTest/java/net/pokeranalytics/android/ExampleInstrumentedUnitTest.kt
@@ -168,23 +168,23 @@ class ExampleInstrumentedUnitTest : RealmInstrumentedUnitTest() {
             Assert.fail("No netbbPer100Hands stat")
         }
 
-        val stdHourly = results.computedStat(Stat.STANDARD_DEVIATION_HOURLY)
-        if (stdHourly != null) {
-            assertEquals(141.42, stdHourly.value, delta)
-        } else {
-            Assert.fail("No stdHourly stat")
-        }
-
         val std = results.computedStat(Stat.STANDARD_DEVIATION)
         if (std != null) {
-            assertEquals(282.84, std.value, delta)
+            assertEquals(200.0, std.value, delta)
         } else {
             Assert.fail("No std stat")
         }
 
+        val stdHourly = results.computedStat(Stat.STANDARD_DEVIATION_HOURLY)
+        if (stdHourly != null) {
+            assertEquals(111.8, stdHourly.value, delta)
+        } else {
+            Assert.fail("No stdHourly stat")
+        }
+
         val std100 = results.computedStat(Stat.STANDARD_DEVIATION_BB_PER_100_HANDS)
         if (std100 != null) {
-            assertEquals(707.1, std100.value, delta)
+            assertEquals(559.01, std100.value, delta)
         } else {
             Assert.fail("No std100 stat")
         }
diff --git a/app/src/main/java/net/pokeranalytics/android/calculus/Calculator.kt b/app/src/main/java/net/pokeranalytics/android/calculus/Calculator.kt
index 348d4312..e97973ff 100644
--- a/app/src/main/java/net/pokeranalytics/android/calculus/Calculator.kt
+++ b/app/src/main/java/net/pokeranalytics/android/calculus/Calculator.kt
@@ -177,24 +177,32 @@ class Calculator {
 
                 ))
 
+            val bbPer100Hands = bbSum / totalHands * 100
+
             // Standard Deviation
             if (options.shouldComputeStandardDeviation()) {
 
+                // Session
                 var stdSum: Double = 0.0
-                sessions.forEach { s ->
-                    stdSum += Math.pow(s.value - average, 2.0)
+                var stdBBper100HandsSum: Double = 0.0
+                sessions.forEach { session ->
+                    stdSum += Math.pow(session.value - average, 2.0)
+                    stdBBper100HandsSum += Math.pow(session.bbPer100Hands - bbPer100Hands, 2.0)
                 }
                 val standardDeviation: Double = Math.sqrt(stdSum / sessions.size)
+                val standardDeviationBBper100Hands: Double = Math.sqrt(stdBBper100HandsSum / sessions.size)
 
+                // Session Set
                 var hourlyStdSum: Double = 0.0
-                sessionSets.forEach { sg ->
-                    hourlyStdSum += Math.pow(sg.hourlyRate - hourlyRate, 2.0)
+                sessionSets.forEach { set ->
+                    hourlyStdSum += Math.pow(set.hourlyRate - hourlyRate, 2.0)
                 }
                 val hourlyStandardDeviation: Double = Math.sqrt(hourlyStdSum / sessionSets.size)
 
                 results.addStats(setOf(
                     ComputedStat(STANDARD_DEVIATION, standardDeviation),
-                    ComputedStat(STANDARD_DEVIATION_HOURLY, hourlyStandardDeviation)
+                    ComputedStat(STANDARD_DEVIATION_HOURLY, hourlyStandardDeviation),
+                    ComputedStat(STANDARD_DEVIATION_BB_PER_100_HANDS, standardDeviationBBper100Hands)
                 ))
             }
 
diff --git a/app/src/main/java/net/pokeranalytics/android/calculus/Computable.kt b/app/src/main/java/net/pokeranalytics/android/calculus/Computable.kt
index 0f01a82a..d4aabc47 100644
--- a/app/src/main/java/net/pokeranalytics/android/calculus/Computable.kt
+++ b/app/src/main/java/net/pokeranalytics/android/calculus/Computable.kt
@@ -18,6 +18,8 @@ interface SessionInterface : Summable {
     var bbNetResult: Double
     var bigBlindSessionCount: Int // 0 or 1
     var buyin: Double
+    var bbPer100Hands: Double
+
 }
 
 /**
diff --git a/app/src/main/java/net/pokeranalytics/android/model/realm/Session.kt b/app/src/main/java/net/pokeranalytics/android/model/realm/Session.kt
index 1fa92055..a210ffd4 100644
--- a/app/src/main/java/net/pokeranalytics/android/model/realm/Session.kt
+++ b/app/src/main/java/net/pokeranalytics/android/model/realm/Session.kt
@@ -237,6 +237,12 @@ open class Session : RealmObject(), SessionInterface, Savable,
 			return 0.0
 		}
 
+	@Ignore
+	override var bbPer100Hands: Double = 0.0
+		get() {
+			return this.bbNetResult / this.estimatedHands * 100.0
+		}
+
 	@Ignore
 	override var bigBlindSessionCount: Int = if (this.cgBigBlind != null) 1 else 0
 
diff --git a/app/src/main/java/net/pokeranalytics/android/model/realm/SessionSet.kt b/app/src/main/java/net/pokeranalytics/android/model/realm/SessionSet.kt
index d05fad74..659787a8 100644
--- a/app/src/main/java/net/pokeranalytics/android/model/realm/SessionSet.kt
+++ b/app/src/main/java/net/pokeranalytics/android/model/realm/SessionSet.kt
@@ -41,6 +41,9 @@ open class SessionSet() : RealmObject() {
 
     @Ignore // a duration shortcut
     var hourlyRate: Double = 0.0
+        get () {
+            return this.netResult / this.hourlyDuration
+        }
 
     @Ignore
     var estimatedHands: Double = 25.0 * (this.timeFrame?.hourlyDuration?.toDouble() ?: 0.0)