diff --git a/README.md b/README.md
index 476c4d6..c242c3b 100644
--- a/README.md
+++ b/README.md
@@ -109,6 +109,24 @@ the shipped config sets `max_authentication_rescan_times` to 0, because at the
 stock budget a wrong finger never yields a terminal frame and a PAM client
 waits forever for the `verify-no-match` it needs.
 
+**Template learning is implemented and OFF, because it makes matching worse on
+this hardware.** Measured, with learning disabled during each measurement so
+nothing moved underneath the numbers:
+
+| template | folds | rate |
+|---|---|---|
+| fresh 20-sample enrolment | 0 | **30/30** |
+| same lineage, later | 40 | 12/15 |
+| same lineage, later still | 185 | total failure |
+
+The frames one press contributes are near-duplicates of a single image from one
+finger position. Folding them spends the template's 96 slots on that position
+and evicts the diversity the enrolment put there. There is no upside to weigh
+against it either: a plain enrolment already measures 30/30, and learning has
+never once been observed to raise a rate under controlled conditions.
+
+`--learn=1` enables it for experiments. What follows describes how it works.
+
 **Template learning.** Stock rewrites the stored template on every successful
 press — `0x1015 UPDATE_TEMPLATE` while the finger is still down, then a deferred
 `SAVE_DATA` — and the stored body measurably grows over a template's life
diff --git a/implementations/main.cpp b/implementations/main.cpp
index 336c33a..0cf6063 100644
--- a/implementations/main.cpp
+++ b/implementations/main.cpp
@@ -117,12 +117,30 @@ bool g_irqObserve = false;
 bool g_edgeWake = false;
 
 // TEMPLATE LEARNING: fold the frames of a successful press back into the
-// stored template, as stock does. On by default because stock does it and
-// because every match rate this project has measured was taken against a
-// day-zero template; `--learn=0` turns it off so the two can be compared on
-// one binary without a rebuild, which is the only way the comparison is
-// single-variable.
-bool g_learn = true;
+// stored template, as stock does.
+//
+// OFF by default, and that is a measured decision rather than caution. Stock
+// does it, this daemon can do it, and on this hardware it makes matching WORSE:
+//
+//   fresh template, 0 folds     30/30   (two consecutive blocks of 15)
+//   same lineage, 40 folds      12/15
+//   same lineage, 185 folds     total failure, 108 consecutive rejections
+//
+// all measured with learning switched off during the measurement itself, so
+// nothing moved underneath the numbers. The mechanism is that the frames one
+// press contributes are near-duplicates of a single image from one finger
+// position, so folding them spends the template's slots -- 96 of them -- on
+// that position and evicts the diversity a 20-sample enrolment put there.
+//
+// And there is no upside to weigh against it: a plain enrolment measures 30/30,
+// so there is nothing for learning to improve. It has never once been observed
+// to raise a rate under controlled conditions; the one run that suggested it
+// did was confounded by a freshly wiped sensor and a user learning the
+// technique, both spotted by Jorijn at the time.
+//
+// `--learn=1` turns it on for experiments. The code stays because the finding
+// is about THIS trustlet's algorithm, not about the idea.
+bool g_learn = false;
 // Dump the trustlet's own log out of the response buffer after every command.
 // See DumpTaLog: on pmOS this is the ONLY way to read it.
 bool g_taLog = false;