diff --git a/shell/readStatsDiff.sh b/shell/readStatsDiff.sh
new file mode 100755
index 000000000..87b97984c
--- /dev/null
+++ b/shell/readStatsDiff.sh
@@ -0,0 +1,66 @@
+#!/usr/bin/csh
+# ##############################################################################
+# this file can be used to diff the flagstat values for a whole genome,
+# along with sub-diffs for each chromosome.  This may be helpful if you're 
+# debugging a specific reads problem, and you want to know the differences
+# between the output of the GATK and samtools
+# ##############################################################################
+
+if ($#argv != 3) then
+    echo "usage readStatsDiff <bamfile.bam> <referenceSequence.fasta> <outputFile>"; exit 1
+endif
+
+if (! -f $1) then
+    echo bam file $2 does not seem to exist; exit 1
+endif
+if (! -f $2) then
+    echo reference file $2 does not seem to exist; exit 1
+endif
+if ( -e $3) then
+    echo output file $3 already exists!; exit 1
+endif
+
+
+# set the bam and the reference index
+set bam = $1
+set seq = $2
+set out = $3
+
+# diff the whole chromosome
+java -ea -Xmx4096m \
+-Xdebug -Xrunjdwp:transport=dt_socket,server=y,suspend=n,address=8015 \
+-jar dist/GenomeAnalysisTK.jar \
+-S SILENT \
+-T FlagStatRead \
+-I $bam \
+-R $seq \
+-oe 1.out 
+samtools flagstat $bam > 2.out
+echo "\n" >> $out
+echo results for whole bam file >> $out
+echo "\n" >> $out
+diff 1.out 2.out >> $out
+rm 1.out
+rm 2.out
+
+
+
+foreach chromosome (chr1 chr2 chr3 chr4 chr5 chr6 chr7 chr8 chr9 chr10 chr11 chr12 chr13 chr14 chr15 chr16 chr17 chr18 chr19 chr20 chr21 chr22 chrX)
+java -ea -Xmx4096m \
+-Xdebug -Xrunjdwp:transport=dt_socket,server=y,suspend=n,address=8015 \
+-jar dist/GenomeAnalysisTK.jar \
+-S SILENT \
+-T FlagStatRead \
+-I $bam \
+-R $seq \
+-oe 1.out \
+-L $chromosome
+samtools view -h -b $bam $chromosome > temp.bam
+samtools flagstat temp.bam > 2.out
+echo results for $chromosome >> $out
+echo "\n" >> $out
+diff 1.out 2.out >> $out
+rm temp.bam
+rm 1.out
+rm 2.out
+end