diff --git a/MUNGA/MOVER.cpp b/MUNGA/MOVER.cpp
index cf06aff..c88c266 100644
--- a/MUNGA/MOVER.cpp
+++ b/MUNGA/MOVER.cpp
@@ -726,6 +726,11 @@ void
 				static Scalar min_percent = 1.0f;
 				static Scalar max_percent = 0.0f;
 				static Scalar worst_error = 0.0f;
+				static Scalar last_distance = 0.0f;
+				static Scalar samples[12];
+				static int sample_count = 0;
+				static int seq_stalls = 0;
+				static int seq_spikes = 0;
 
 				++steps;
 				if (have_last)
@@ -734,6 +739,43 @@ void
 					moved.Subtract(localOrigin.linearPosition, last_pos);
 					Scalar distance = moved.Length();
 
+					//
+					// The same test the renderer applies to drawn frames:
+					// this step against the one before it, not against a
+					// running mean.
+					//
+					// A running mean is blind to an alternating pattern -
+					// high, low, high, low averages to the mean and nothing
+					// ever looks anomalous - which is why this trace has
+					// been reporting zero spikes and zero stalls while the
+					// renderer, comparing consecutive frames, counted
+					// fifteen to forty-six stalls in the same motion. The
+					// mean test only ever ruled out DRIFT.
+					//
+					if (distance < 50.0f)
+					{
+						if (last_distance > 0.001f)
+						{
+							Scalar sequential = distance / last_distance;
+
+							if (sequential < 0.4f)		{ ++seq_stalls; }
+							else if (sequential > 2.5f)	{ ++seq_spikes; }
+						}
+						last_distance = distance;
+
+						//
+						// And keep a few consecutive steps verbatim, so the
+						// shape can be READ rather than inferred from
+						// counters. Twelve steps is a quarter second at
+						// 50Hz - long enough to show a beat, short enough
+						// to fit one line.
+						//
+						if (sample_count < 12)
+						{
+							samples[sample_count++] = distance;
+						}
+					}
+
 					if (distance > 50.0f)
 					{
 						mean_step = 0.0f;		// respawn, not motion
@@ -766,6 +808,15 @@ void
 							<< "s worst miss " << worst_error << "s\n"
 							<< std::flush;
 
+						DEBUG_STREAM << "CamLog: replicant sequence - "
+							<< seq_stalls << " stall(s), " << seq_spikes
+							<< " spike(s) against the PREVIOUS step; steps:";
+						for (int s = 0; s < sample_count; s++)
+						{
+							DEBUG_STREAM << " " << samples[s];
+						}
+						DEBUG_STREAM << "\n" << std::flush;
+
 						DEBUG_STREAM << "CamLog: replicant arrivals - widest gap "
 							<< widestGap << "s, " << longGapCount
 							<< " long, " << queuedGapCount
@@ -788,6 +839,9 @@ void
 					min_percent = 1.0f;
 					max_percent = 0.0f;
 					worst_error = 0.0f;
+					sample_count = 0;
+					seq_stalls = 0;
+					seq_spikes = 0;
 				}
 				{
 					Scalar missed =