Index: lucene/misc/src/java/org/apache/lucene/index/sorter/NumericDocValuesSorter.java
===================================================================
--- lucene/misc/src/java/org/apache/lucene/index/sorter/NumericDocValuesSorter.java	(revision 1466166)
+++ lucene/misc/src/java/org/apache/lucene/index/sorter/NumericDocValuesSorter.java	(working copy)
@@ -24,37 +24,58 @@
 
 /**
  * A {@link Sorter} which sorts documents according to their
- * {@link NumericDocValues}.
- *
+ * {@link NumericDocValues}. One can specify ascending or descending sort order.
+ * 
  * @lucene.experimental
  */
 public class NumericDocValuesSorter extends Sorter {
 
   private final String fieldName;
-
+  private final boolean ascending;
+  
+  /** Constructor over the given field name, and ascending sort order. */
   public NumericDocValuesSorter(final String fieldName) {
+    this(fieldName, true);
+  }
+  
+  /**
+   * Constructor over the given field name, and whether sorting should be
+   * ascending ({@code true}) or descending ({@code false}).
+   */
+  public NumericDocValuesSorter(final String fieldName, boolean ascending) {
     this.fieldName = fieldName;
+    this.ascending = ascending;
   }
 
   @Override
   public Sorter.DocMap sort(final AtomicReader reader) throws IOException {
     final NumericDocValues ndv = reader.getNumericDocValues(fieldName);
-    final DocComparator comparator = new DocComparator() {
-
-      @Override
-      public int compare(int docID1, int docID2) {
-        final long v1 = ndv.get(docID1);
-        final long v2 = ndv.get(docID2);
-        return v1 < v2 ? -1 : v1 == v2 ? 0 : 1;
-      }
-      
-    };
+    final DocComparator comparator;
+    if (ascending) {
+      comparator = new DocComparator() {
+        @Override
+        public int compare(int docID1, int docID2) {
+          final long v1 = ndv.get(docID1);
+          final long v2 = ndv.get(docID2);
+          return v1 < v2 ? -1 : v1 == v2 ? 0 : 1;
+        }
+      };
+    } else {
+      comparator = new DocComparator() {
+        @Override
+        public int compare(int docID1, int docID2) {
+          final long v1 = ndv.get(docID1);
+          final long v2 = ndv.get(docID2);
+          return v1 > v2 ? -1 : v1 == v2 ? 0 : 1;
+        }
+      };
+    }
     return sort(reader.maxDoc(), comparator);
   }
   
   @Override
   public String getID() {
-    return "DocValues(" + fieldName + ",asc)";
+    return "DocValues(" + fieldName + "," + (ascending ? "ascending" : "descending") + ")";
   }
   
 }
Index: lucene/misc/src/java/org/apache/lucene/index/sorter/Sorter.java
===================================================================
--- lucene/misc/src/java/org/apache/lucene/index/sorter/Sorter.java	(revision 1466166)
+++ lucene/misc/src/java/org/apache/lucene/index/sorter/Sorter.java	(working copy)
@@ -81,6 +81,47 @@
 
   }
 
+  /** Sorts documents in reverse order of a wrapped {@link Sorter}. */
+  public static final class ReverseOrderSorter extends Sorter {
+
+    private final Sorter in;
+    
+    public ReverseOrderSorter(Sorter in) {
+      if (in == REVERSE_DOCS || in instanceof ReverseOrderSorter) {
+        throw new IllegalArgumentException("reversing the order of a reversing sorter doesn't make any sense!");
+      }
+      this.in = in;
+    }
+    
+    @Override
+    public DocMap sort(final AtomicReader reader) throws IOException {
+      final int maxDoc = reader.maxDoc();
+      final DocMap inMap = in.sort(reader);
+      return new DocMap() {
+        @Override
+        public int oldToNew(int docID) {
+          return maxDoc - inMap.oldToNew(docID) - 1;
+        }
+        
+        @Override
+        public int newToOld(int docID) {
+          return inMap.newToOld(maxDoc - docID -1);
+        }
+        
+        @Override
+        public int size() {
+          return inMap.size();
+        }
+        
+      };
+    }
+    
+    @Override
+    public String getID() {
+      return "Reverse(" + in.getID() + ")";
+    }
+  }
+
   /** Sorts documents in reverse order.
    *  <b>NOTE</b>: This {@link Sorter} is not idempotent. Sorting an
    *  {@link AtomicReader} once or twice will return two different
@@ -111,7 +152,7 @@
       return "ReverseDocs";
     }
   };
-
+  
   private static final class DocValueSorterTemplate extends SorterTemplate {
     
     private final int[] docs;
@@ -231,4 +272,9 @@
    */
   public abstract String getID();
 
+  @Override
+  public String toString() {
+    return getID();
+  }
+  
 }
Index: lucene/misc/src/test/org/apache/lucene/index/sorter/IndexSortingTest.java
===================================================================
--- lucene/misc/src/test/org/apache/lucene/index/sorter/IndexSortingTest.java	(revision 1466166)
+++ lucene/misc/src/test/org/apache/lucene/index/sorter/IndexSortingTest.java	(working copy)
@@ -32,7 +32,7 @@
 public class IndexSortingTest extends SorterTestBase {
   
   private static final Sorter[] SORTERS = new Sorter[] {
-    new NumericDocValuesSorter(NUMERIC_DV_FIELD),
+    new NumericDocValuesSorter(NUMERIC_DV_FIELD, true),
     Sorter.REVERSE_DOCS,
   };
   
@@ -52,6 +52,13 @@
       Collections.reverse(values);
     } else {
       Collections.sort(values);
+      if (sorter instanceof NumericDocValuesSorter && random().nextBoolean()) {
+        sorter = new NumericDocValuesSorter(NUMERIC_DV_FIELD, false); // descending
+        Collections.reverse(values);
+      } else if (random().nextBoolean()) { // wrap with reverse order 
+        sorter = new Sorter.ReverseOrderSorter(sorter);
+        Collections.reverse(values);
+      }
     }
     sortedValues = values.toArray(new Integer[values.size()]);
     if (VERBOSE) {