diff --git a/rhino/aliases/cmd/smart_join.py b/rhino/aliases/cmd/smart_join.py
index 0c7aac3..1bcb3b7 100644
--- a/rhino/aliases/cmd/smart_join.py
+++ b/rhino/aliases/cmd/smart_join.py
@@ -145,23 +145,35 @@ def _t_join_attempt(doc, sel):
     tol_snap = 0.20  # 20 cm Snap-Radius fuer T-Verbindung
     end_tol = 0.05   # 5cm: wenn closest-point nahe Endpunkt → eigentlich L
     candidates = []
+    debug_rows = []
     # Pro Endpunkt der einen Kurve: ClosestPoint auf der ANDEREN Kurve
     for (a_obj, ac, b_obj, bc) in ((o1, c1, o2, c2), (o2, c2, o1, c1)):
         for end in (0, 1):
             ep = ac.PointAtStart if end == 0 else ac.PointAtEnd
             try:
                 rc, t = bc.ClosestPoint(ep)
-                if not rc: continue
+                if not rc:
+                    debug_rows.append(("axis_end={}".format(end), "ClosestPoint failed"))
+                    continue
                 cp = bc.PointAt(t)
                 d = cp.DistanceTo(ep)
-                # Skip wenn schon snapped oder zu weit
-                if d < 1e-6 or d > tol_snap: continue
-                # Skip wenn cp nahe einem Endpunkt von bc — das ist L-Join Territory
                 ps = bc.PointAtStart; pe = bc.PointAtEnd
-                if cp.DistanceTo(ps) < end_tol or cp.DistanceTo(pe) < end_tol:
-                    continue
-                candidates.append((d, a_obj, ac, end, cp))
-            except Exception: continue
+                d_to_ps = cp.DistanceTo(ps)
+                d_to_pe = cp.DistanceTo(pe)
+                reason = None
+                if d < 1e-6: reason = "schon gesnappt"
+                elif d > tol_snap: reason = "zu weit ({:.3f} > {:.2f})".format(d, tol_snap)
+                elif d_to_ps < end_tol: reason = "cp nahe Endpunkt-Start ({:.3f}<{:.2f}) → L-Join Sache".format(d_to_ps, end_tol)
+                elif d_to_pe < end_tol: reason = "cp nahe Endpunkt-End ({:.3f}<{:.2f}) → L-Join Sache".format(d_to_pe, end_tol)
+                debug_rows.append(("axis_end={} d={:.3f}".format(end, d),
+                                     reason or "candidate"))
+                if reason is None:
+                    candidates.append((d, a_obj, ac, end, cp))
+            except Exception as ex:
+                debug_rows.append(("axis_end={}".format(end), "exc: {}".format(ex)))
+    # Diagnostic alles ausgeben
+    for tag, msg in debug_rows:
+        print("[SMART-JOIN] T-Join check {}: {}".format(tag, msg))
     if not candidates: return False
     # Naechster Endpunkt → der wird gesnappt
     candidates.sort(key=lambda x: x[0])