diff --git a/common-tools/clas-analysis/src/main/java/org/jlab/analysis/nabo/Efficiency.java b/common-tools/clas-analysis/src/main/java/org/jlab/analysis/nabo/Efficiency.java
new file mode 100644
index 000000000..2958045ce
--- /dev/null
+++ b/common-tools/clas-analysis/src/main/java/org/jlab/analysis/nabo/Efficiency.java
@@ -0,0 +1,124 @@
+package org.jlab.analysis.nabo;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
+import java.util.TreeMap;
+import java.util.stream.IntStream;
+import org.jlab.jnp.hipo4.data.Bank;
+import org.jlab.jnp.hipo4.data.Event;
+import org.jlab.jnp.hipo4.data.Schema;
+import org.jlab.jnp.hipo4.data.SchemaFactory;
+import org.jlab.jnp.hipo4.io.HipoReader;
+
+public class Efficiency {
+
+    static final List<Integer> NEGATIVES = Arrays.asList(11, -211, -321, -2212);
+    static final List<Integer> POSITIVES = Arrays.asList(11, 211, 321, 2212);
+    static final List<Integer> NEUTRALS = Arrays.asList(22, 2112);
+    static List<Integer> PIDS;
+    
+    Schema mcGenMatch;
+    Schema mcParticle;
+    Schema recParticle;
+    int[][] caches;
+
+    public static void main(String[] args) {
+        Efficiency e = new Efficiency(args);
+        System.out.println(e);
+    }
+
+    private void init(SchemaFactory schema) {
+        PIDS = new ArrayList(NEGATIVES);
+        PIDS.addAll(POSITIVES);
+        PIDS.addAll(NEUTRALS);
+        caches = new int[PIDS.size()][PIDS.size()];
+        mcGenMatch = schema.getSchema("MC::GenMatch");
+        mcParticle = schema.getSchema("MC::Particle");
+        recParticle = schema.getSchema("REC::Particle");
+    }
+
+    public Efficiency(SchemaFactory schema) {
+        init(schema);
+    }
+
+    public Efficiency(String... filenames) {
+        HipoReader r = new HipoReader();
+        r.open(filenames[0]);
+        init(r.getSchemaFactory());
+        r.close();
+        add(filenames);
+    }
+
+    public float get(int mc, int rec) {
+        long sum = IntStream.of(caches[PIDS.indexOf(mc)]).sum();
+        return sum>0 ? caches[PIDS.indexOf(mc)][PIDS.indexOf(rec)]/sum : 0;
+    }
+
+    public float get(int pid) {
+        return get(pid,pid);
+    }
+
+    @Override
+    public String toString() {
+        StringBuilder s = new StringBuilder();
+        s.append("      ");
+        for (int i=0; i<PIDS.size(); ++i) {
+            s.append(String.format("%7d",PIDS.get(i)));
+            if (PIDS.size()==i+1) s.append("\n");
+        }
+        for (int i=0; i<PIDS.size(); ++i) {
+            s.append(String.format("%6d",PIDS.get(i)));
+            for (int j=0; j<PIDS.size(); ++j) {
+                s.append(String.format("%7.4f",get(PIDS.get(i),PIDS.get(j))));
+                if (PIDS.size()==j+1) s.append("\n");
+            }
+        }
+        return s.toString();
+    }
+    
+    public void add(int mc, int rec) {
+        if (PIDS.contains(mc)) {
+            if (!PIDS.contains(rec)) add(mc);
+            else caches[PIDS.indexOf(mc)][PIDS.indexOf(rec)]++;
+        }
+    }
+
+    public void add(int mc) {
+        add(mc, 0);
+    }
+
+    public void add(Event e) {
+        Bank bm = new Bank(mcParticle);
+        Bank br = new Bank(recParticle);
+        e.read(bm);
+        e.read(br);
+        TreeMap<Short,Short> good = getMapping(e);
+        for (short row=0; row<bm.getRows(); ++row) {
+            if (!good.containsKey(row)) add(bm.getInt("pid",row));
+            else add(bm.getInt("pid",row), br.getInt("pid",good.get(row)));
+        }
+    }
+
+    public void add(String... filename) {
+        Event e = new Event();
+        for (String f : filename) {
+            HipoReader r = new HipoReader();
+            r.open(f);
+            while (r.hasNext()) {
+                r.nextEvent(e);
+                add(e);
+            }
+        }
+    }
+    
+    private TreeMap getMapping(Event e) {
+        Bank b = new Bank(mcGenMatch);
+        e.read(b);
+        TreeMap<Short,Short> m = new TreeMap<>();
+        for (int row=0; row<b.getRows(); ++row)
+            m.put(b.getShort("mcindex", row),b.getShort("pindex",row));
+        return m;
+    }
+
+}