diff --git a/reckon-core/src/main/java/org/ajoberstar/reckon/core/Reckoner.java b/reckon-core/src/main/java/org/ajoberstar/reckon/core/Reckoner.java
index ee914b7a..1779f581 100644
--- a/reckon-core/src/main/java/org/ajoberstar/reckon/core/Reckoner.java
+++ b/reckon-core/src/main/java/org/ajoberstar/reckon/core/Reckoner.java
@@ -1,6 +1,7 @@
 package org.ajoberstar.reckon.core;
 
 import java.util.Arrays;
+import java.util.Objects;
 import java.util.Optional;
 import java.util.Set;
 import java.util.function.BiFunction;
@@ -8,6 +9,9 @@
 import java.util.stream.Collectors;
 import java.util.stream.Stream;
 
+import org.ajoberstar.reckon.core.git.GitInventorySupplier;
+import org.eclipse.jgit.lib.Repository;
+
 public final class Reckoner {
   public static final String FINAL_STAGE = "final";
   public static final String SNAPSHOT_STAGE = "snapshot";
@@ -66,7 +70,7 @@ private Version reckonNormal(VcsInventory inventory) {
       targetNormal = targetNormal.incrementNormal(scope);
     }
 
-    if (inventory.getClaimedVersions().contains(targetNormal)) {
+    if (inventory.getClaimedVersions().contains(targetNormal) && !inventory.getCurrentVersion().filter(targetNormal::equals).isPresent()) {
       throw new IllegalStateException("Reckoned target normal version " + targetNormal + " has already been released.");
     }
 
@@ -133,6 +137,11 @@ public Builder vcs(VcsInventorySupplier inventorySupplier) {
       return this;
     }
 
+    public Builder git(Repository repo) {
+      this.inventorySupplier = new GitInventorySupplier(repo);
+      return this;
+    }
+
     public Builder scopeCalc(Function<VcsInventory, Optional<String>> scopeCalc) {
       this.scopeCalc = scopeCalc;
       return this;
@@ -160,6 +169,10 @@ public Builder stageCalc(BiFunction<VcsInventory, Version, Optional<String>> sta
     }
 
     public Reckoner build() {
+      Objects.requireNonNull(inventorySupplier, "Must provide a vcs.");
+      Objects.requireNonNull(scopeCalc, "Must provide a scope supplier.");
+      Objects.requireNonNull(stages, "Must provide set of stages.");
+      Objects.requireNonNull(stageCalc, "Must provide a stage supplier.");
       return new Reckoner(inventorySupplier, scopeCalc, stageCalc, stages, defaultStage);
     }
   }
diff --git a/reckon-core/src/test/groovy/org/ajoberstar/reckon/core/ReckonerTest.groovy b/reckon-core/src/test/groovy/org/ajoberstar/reckon/core/ReckonerTest.groovy
index 2c572bf6..a9b220c2 100644
--- a/reckon-core/src/test/groovy/org/ajoberstar/reckon/core/ReckonerTest.groovy
+++ b/reckon-core/src/test/groovy/org/ajoberstar/reckon/core/ReckonerTest.groovy
@@ -178,7 +178,7 @@ class ReckonerTest extends Specification {
     def inventory = new VcsInventory(
       'abcdef',
       true,
-      null,
+      Version.valueOf('0.1.0'),
       Version.valueOf('0.0.0'),
       Version.valueOf('0.0.0'),
       1,
diff --git a/reckon-gradle/src/compatTest/groovy/org/ajoberstar/reckon/gradle/BaseCompatTest.groovy b/reckon-gradle/src/compatTest/groovy/org/ajoberstar/reckon/gradle/BaseCompatTest.groovy
index 3eb5c099..a52e49ed 100644
--- a/reckon-gradle/src/compatTest/groovy/org/ajoberstar/reckon/gradle/BaseCompatTest.groovy
+++ b/reckon-gradle/src/compatTest/groovy/org/ajoberstar/reckon/gradle/BaseCompatTest.groovy
@@ -72,7 +72,7 @@ task printVersion {
     when:
     def result = buildAndFail('printVersion')
     then:
-    result.output.contains('Must provide strategies for normal and preRelease on the reckon extension.')
+    result.output.contains('Must provide a scope supplier.')
   }
 
   def 'if reckoned version has build metadata no tag created'() {
@@ -86,8 +86,8 @@ plugins {
 }
 
 reckon {
-  normal = scopeFromProp()
-  preRelease = stageFromProp('alpha','beta', 'final')
+  scopeFromProp()
+  stageFromProp('alpha','beta', 'final')
 }
 """
     local.add(patterns: ['build.gradle'])
@@ -111,8 +111,8 @@ plugins {
 }
 
 reckon {
-  normal = scopeFromProp()
-  preRelease = stageFromProp('alpha','beta', 'final')
+  scopeFromProp()
+  stageFromProp('alpha','beta', 'final')
 }
 """
     local.add(patterns: ['build.gradle'])
@@ -139,8 +139,8 @@ plugins {
 }
 
 reckon {
-  normal = scopeFromProp()
-  preRelease = stageFromProp('alpha','beta', 'final')
+  scopeFromProp()
+  stageFromProp('alpha', 'beta', 'final')
 }
 """
     local.add(patterns: ['build.gradle'])
diff --git a/reckon-gradle/src/main/java/org/ajoberstar/reckon/gradle/ReckonExtension.java b/reckon-gradle/src/main/java/org/ajoberstar/reckon/gradle/ReckonExtension.java
index 15ba7d80..f74c07f8 100644
--- a/reckon-gradle/src/main/java/org/ajoberstar/reckon/gradle/ReckonExtension.java
+++ b/reckon-gradle/src/main/java/org/ajoberstar/reckon/gradle/ReckonExtension.java
@@ -1,23 +1,10 @@
 package org.ajoberstar.reckon.gradle;
 
-import java.util.Arrays;
 import java.util.Optional;
-import java.util.Set;
-import java.util.function.BiFunction;
-import java.util.function.Function;
-import java.util.stream.Collectors;
 
 import org.ajoberstar.grgit.Grgit;
-import org.ajoberstar.reckon.core.NormalStrategy;
-import org.ajoberstar.reckon.core.PreReleaseStrategy;
 import org.ajoberstar.reckon.core.Reckoner;
-import org.ajoberstar.reckon.core.VcsInventory;
 import org.ajoberstar.reckon.core.VcsInventorySupplier;
-import org.ajoberstar.reckon.core.Version;
-import org.ajoberstar.reckon.core.git.GitInventorySupplier;
-import org.ajoberstar.reckon.core.strategy.ScopeNormalStrategy;
-import org.ajoberstar.reckon.core.strategy.SnapshotPreReleaseStrategy;
-import org.ajoberstar.reckon.core.strategy.StagePreReleaseStrategy;
 import org.gradle.api.Project;
 
 public class ReckonExtension {
@@ -27,44 +14,51 @@ public class ReckonExtension {
 
   private Project project;
   private Grgit grgit;
-  private VcsInventorySupplier vcsInventory;
-  private NormalStrategy normal;
-  private PreReleaseStrategy preRelease;
+  private Reckoner.Builder reckoner;
 
   public ReckonExtension(Project project) {
     this.project = project;
+    this.reckoner = Reckoner.builder();
   }
 
-  public void setVcsInventory(VcsInventorySupplier vcsInventory) {
-    this.vcsInventory = vcsInventory;
+  @Deprecated
+  public void setVcsInventory(VcsInventorySupplier inventorySupplier) {
+    project.getLogger().warn("reckon.vcsInventory = <vcs> is deprecated and will be removed in 1.0.0. Call reckon.git instead.");
+    this.reckoner.vcs(inventorySupplier);
   }
 
-  public void setNormal(NormalStrategy normal) {
-    this.normal = normal;
+  @Deprecated
+  public void setNormal(ReckonExtension ext) {
+    project.getLogger().warn("reckon.normal = scopeFromProp() is deprecated and will be removed in 1.0.0. Call reckon.scopeFromProp() instead.");
+    // no op
   }
 
-  public void setPreRelease(PreReleaseStrategy preRelease) {
-    this.preRelease = preRelease;
+  @Deprecated
+  public void setPreRelease(ReckonExtension ext) {
+    project.getLogger().warn("reckon.preRelease = stageFromProp() or snapshotFromProp() is deprecated and will be removed in 1.0.0. Call reckon.stageFromProp() or reckon.snapshotFromProp() instead.");
+    // no op
   }
 
-  public VcsInventorySupplier git(Grgit grgit) {
+  public ReckonExtension git(Grgit grgit) {
     this.grgit = grgit;
-    return new GitInventorySupplier(grgit.getRepository().getJgit().getRepository());
+    this.reckoner.git(grgit.getRepository().getJgit().getRepository());
+    return this;
   }
 
-  public NormalStrategy scopeFromProp() {
-    Function<VcsInventory, Optional<String>> supplier = inventory -> findProperty(SCOPE_PROP);
-    return new ScopeNormalStrategy(supplier);
+  public ReckonExtension scopeFromProp() {
+    this.reckoner.scopeCalc(inventory -> findProperty(SCOPE_PROP));
+    return this;
   }
 
-  public PreReleaseStrategy stageFromProp(String... stages) {
-    Set<String> stageSet = Arrays.stream(stages).collect(Collectors.toSet());
-    BiFunction<VcsInventory, Version, Optional<String>> supplier = (inventory, targetNormal) -> findProperty(STAGE_PROP);
-    return new StagePreReleaseStrategy(stageSet, supplier);
+  public ReckonExtension stageFromProp(String... stages) {
+    this.reckoner.stages(stages);
+    this.reckoner.stageCalc((inventory, targetNormal) -> findProperty(STAGE_PROP));
+    return this;
   }
 
-  public PreReleaseStrategy snapshotFromProp() {
-    BiFunction<VcsInventory, Version, Optional<String>> supplier = (inventory, targetNormal) -> {
+  public ReckonExtension snapshotFromProp() {
+    this.reckoner.snapshots();
+    this.reckoner.stageCalc((inventory, targetNormal) -> {
       Optional<String> stageProp = findProperty(STAGE_PROP);
       Optional<String> snapshotProp = findProperty(SNAPSHOT_PROP)
           .map(Boolean::parseBoolean)
@@ -75,8 +69,8 @@ public PreReleaseStrategy snapshotFromProp() {
       });
 
       return stageProp.isPresent() ? stageProp : snapshotProp;
-    };
-    return new SnapshotPreReleaseStrategy(supplier);
+    });
+    return this;
   }
 
   private Optional<String> findProperty(String name) {
@@ -91,13 +85,11 @@ Grgit getGrgit() {
   }
 
   String reckonVersion() {
-    if (vcsInventory == null) {
+    if (grgit == null) {
       project.getLogger().warn("No VCS found/configured. Version will be 'unspecified'.");
       return "unspecified";
-    } else if (normal == null || preRelease == null) {
-      throw new IllegalStateException("Must provide strategies for normal and preRelease on the reckon extension.");
     } else {
-      String version = Reckoner.reckon(vcsInventory, normal, preRelease);
+      String version = reckoner.build().reckon().toString();
       project.getLogger().warn("Reckoned version: {}", version);
       return version;
     }
diff --git a/reckon-gradle/src/main/java/org/ajoberstar/reckon/gradle/ReckonPlugin.java b/reckon-gradle/src/main/java/org/ajoberstar/reckon/gradle/ReckonPlugin.java
index 0fce6e55..3bf6fb70 100644
--- a/reckon-gradle/src/main/java/org/ajoberstar/reckon/gradle/ReckonPlugin.java
+++ b/reckon-gradle/src/main/java/org/ajoberstar/reckon/gradle/ReckonPlugin.java
@@ -25,7 +25,7 @@ public void apply(Project project) {
     project.getPluginManager().withPlugin("org.ajoberstar.grgit", plugin -> {
       Grgit grgit = (Grgit) project.findProperty("grgit");
       if (grgit != null) {
-        extension.setVcsInventory(extension.git(grgit));
+        extension.git(grgit);
       }
     });