diff --git a/public/java/src/org/broadinstitute/sting/gatk/walkers/qc/AssessReducedQuals.java b/public/java/src/org/broadinstitute/sting/gatk/walkers/qc/AssessReducedQuals.java
index c8ec33364..e74684c53 100644
--- a/public/java/src/org/broadinstitute/sting/gatk/walkers/qc/AssessReducedQuals.java
+++ b/public/java/src/org/broadinstitute/sting/gatk/walkers/qc/AssessReducedQuals.java
@@ -1,5 +1,6 @@
 package org.broadinstitute.sting.gatk.walkers.qc;
 
+import org.broadinstitute.sting.commandline.Argument;
 import org.broadinstitute.sting.commandline.Output;
 import org.broadinstitute.sting.gatk.contexts.AlignmentContext;
 import org.broadinstitute.sting.gatk.contexts.ReferenceContext;
@@ -7,73 +8,125 @@ import org.broadinstitute.sting.gatk.refdata.RefMetaDataTracker;
 import org.broadinstitute.sting.gatk.walkers.LocusWalker;
 import org.broadinstitute.sting.gatk.walkers.TreeReducible;
 import org.broadinstitute.sting.utils.GenomeLoc;
+import org.broadinstitute.sting.utils.MathUtils;
 import org.broadinstitute.sting.utils.pileup.PileupElement;
 import org.broadinstitute.sting.utils.pileup.ReadBackedPileup;
 
 import java.io.PrintStream;
+import java.util.List;
 
 /**
- * Created with IntelliJ IDEA.
- * User: ami
- * Date: 10/19/12
- * Time: 9:09 AM
- * To change this template use File | Settings | File Templates.
+ * Emits intervals in which the differences between the original and reduced bam quals are bigger epsilon (unless the quals of
+ * the reduced bam are above sufficient threshold)
+ *
+ * <h2>Input</h2>
+ * <p>
+ * The original and reduced BAM files.
+ * </p>
+ *
+ * <h2>Output</h2>
+ * <p>
+ * A list of intervals in which the differences between the original and reduced bam quals are bigger epsilon.
+ * </p>
+ *
+ * <h2>Examples</h2>
+ * <pre>
+ * java -Xmx2g -jar GenomeAnalysisTK.jar \
+ *   -I:original original.bam \
+ *   -I:reduced reduced.bam \
+ *   -R ref.fasta \
+ *   -T AssessReducedQuals \
+ *   -o output.intervals
+ * </pre>
+ *
+ * @author ami
  */
+
 public class AssessReducedQuals extends LocusWalker<GenomeLoc, GenomeLoc> implements TreeReducible<GenomeLoc> {
 
-    private static final String original = "original";
     private static final String reduced = "reduced";
+    private static final String original = "original";
+    private static final int originalQualsIndex = 0;
+    private static final int reducedQualsIndex = 1;
+
+    @Argument(fullName = "sufficientQualSum", shortName = "sufficientQualSum", doc = "When a reduced bam qual sum is above this threshold, it passes even without comparing to the non-reduced bam ", required = false)
+    public int sufficientQualSum = 600;
+
+    @Argument(fullName = "qual_epsilon", shortName = "epsilon", doc = "when |Quals_reduced_bam - Quals_original_bam| > epsilon*Quals_original_bam we output this interval", required = false)
+    public int qual_epsilon = 0;
+
+    @Argument(fullName = "debugLevel", shortName = "debug", doc = "debug mode on")
+    public int debugLevel = 0;
 
     @Output
     protected PrintStream out;
 
+    public void initialize() {
+        if (debugLevel != 0)
+            out.println("  Debug mode" +
+                        "Debug:\tsufficientQualSum: "+sufficientQualSum+ "\n " +
+                        "Debug:\tqual_epsilon: "+qual_epsilon);
+    }
+
     @Override
     public boolean includeReadsWithDeletionAtLoci() { return true; }
 
-    public void initialize() {}    //todo: why we need that?
-
     @Override
     public GenomeLoc map(RefMetaDataTracker tracker, ReferenceContext ref, AlignmentContext context) {
         if ( tracker == null )
             return null;
 
-        int originalQualsIndex = 0;
-        int reducedQualsIndex = 1;
-        double epsilon = 0;
-        double[] quals = getPileupQuals(context.getBasePileup());
-        return (quals[originalQualsIndex] - quals[reducedQualsIndex] >= epsilon || quals[originalQualsIndex] - quals[reducedQualsIndex] <= -1*epsilon) ? ref.getLocus() : null;
+        boolean reportLocus;
+        final int[] quals = getPileupQuals(context.getBasePileup());
+        if (debugLevel != 0)
+            out.println("Debug:\tLocus Quals\t"+ref.getLocus()+"\toriginal\t"+quals[originalQualsIndex]+"\treduced\t"+quals[reducedQualsIndex]);
+        final int epsilon = MathUtils.fastRound(quals[originalQualsIndex]*qual_epsilon);
+        final int calcOriginalQuals = Math.min(quals[originalQualsIndex],sufficientQualSum);
+        final int calcReducedQuals = Math.min(quals[reducedQualsIndex],sufficientQualSum);
+        final int OriginalReducedQualDiff = calcOriginalQuals - calcReducedQuals;
+        reportLocus = OriginalReducedQualDiff > epsilon || OriginalReducedQualDiff < -1*epsilon;
+        if(debugLevel != 0 && reportLocus)
+            out.println("Debug:\tEmited Locus\t"+ref.getLocus()+"\toriginal\t"+quals[originalQualsIndex]+"\treduced\t"+quals[reducedQualsIndex]+"\tepsilon\t"+epsilon+"\tdiff\t"+OriginalReducedQualDiff);
 
+        return reportLocus ? ref.getLocus() : null;
     }
 
-    private double[] getPileupQuals(final ReadBackedPileup readPileup) {
+    private final int[] getPileupQuals(final ReadBackedPileup readPileup) {
 
-        int originalQualsIndex = 0;
-        int reducedQualsIndex = 1;
-        double[] quals = new double[2];
+        final int[] quals = new int[2];
+        String[] printPileup = {"Debug 2:\toriginal pileup:\t"+readPileup.getLocation()+"\nDebug 2:----------------------------------\n",
+                                "Debug 2:\t reduced pileup:\t"+readPileup.getLocation()+"\nDebug 2:----------------------------------\n"};
 
-        for( PileupElement p : readPileup){
-            if ( (int)p.getQual() > 2 && p.getMappingQual() > 0 && !p.isDeletion() ){
-                if (p.getRead().isReducedRead()){
-                    double tempQual = (double)(p.getQual()) * p.getRepresentativeCount();
-                    quals[reducedQualsIndex] += tempQual;
-                }
-                else
-                {
-                    double tempQual = (double)(p.getQual());
-                    quals[originalQualsIndex] += tempQual;
-                }
+        for( PileupElement p : readPileup ){
+            final List<String> tags = getToolkit().getReaderIDForRead(p.getRead()).getTags().getPositionalTags();
+            if ( isGoodRead(p,tags) ){
+                final int tempQual = (int)(p.getQual()) * p.getRepresentativeCount();
+                final int tagIndex = getTagIndex(tags);
+                quals[tagIndex] += tempQual;
+                if(debugLevel == 2)
+                    printPileup[tagIndex] += "\tDebug 2: ("+p+")\tMQ="+p.getMappingQual()+":QU="+p.getQual()+":RC="+p.getRepresentativeCount()+":OS="+p.getOffset()+"\n";
             }
-
         }
-
-
+        if(debugLevel == 2){
+            out.println(printPileup[originalQualsIndex]);
+            out.println(printPileup[reducedQualsIndex]);
+        }
         return quals;
     }
 
-    //public void onTraversalDone(GenomeLoc sum) {
-    //    if ( sum != null )
-    //        out.println(sum);
-    //}
+    private final boolean isGoodRead(PileupElement p, List<String> tags){
+        return !p.isDeletion() && (tags.contains(reduced) || (tags.contains(original) && (int)p.getQual() >= 20 && p.getMappingQual() >= 20));
+    }
+
+    private final int getTagIndex(List<String> tags){
+        return tags.contains(reduced) ? 1 : 0;
+    }
+
+    @Override
+    public void onTraversalDone(GenomeLoc sum) {
+        if ( sum != null )
+            out.println(sum);
+    }
 
     @Override
     public GenomeLoc treeReduce(GenomeLoc lhs, GenomeLoc rhs) {
diff --git a/public/scala/qscript/org/broadinstitute/sting/queue/qscripts/GATKResourcesBundle.scala b/public/scala/qscript/org/broadinstitute/sting/queue/qscripts/GATKResourcesBundle.scala
index 5e66520ca..9e8815762 100755
--- a/public/scala/qscript/org/broadinstitute/sting/queue/qscripts/GATKResourcesBundle.scala
+++ b/public/scala/qscript/org/broadinstitute/sting/queue/qscripts/GATKResourcesBundle.scala
@@ -136,7 +136,14 @@ class GATKResourcesBundle extends QScript {
 
     addResource(new Resource("/humgen/gsa-hpprojects/GATK/data/Comparisons/Unvalidated/GoldStandardIndel/gold.standard.indel.MillsAnd1000G.b37.vcf",
       "Mills_and_1000G_gold_standard.indels", b37, true, false))
-    
+
+    //
+    // CEU trio (NA12878,NA12891,NA12892) best practices results (including PBT)
+    //
+
+    addResource(new Resource("/humgen/gsa-hpprojects/NA12878Collection/callsets/CEUtrio_BestPractices/current/CEUTrio.HiSeq.WGS.b37.UG.snps_and_indels.recalibrated.filtered.phaseByTransmission.vcf",
+      "CEUTrio.HiSeq.WGS.b37.UG.bestPractices.phaseByTransmission",b37,true,false))
+
     //
     // example call set for wiki tutorial
     //