diff --git a/clang/docs/HardwareAssistedAddressSanitizerDesign.rst b/clang/docs/HardwareAssistedAddressSanitizerDesign.rst
--- a/clang/docs/HardwareAssistedAddressSanitizerDesign.rst
+++ b/clang/docs/HardwareAssistedAddressSanitizerDesign.rst
@@ -131,7 +131,8 @@
     https://www.kernel.org/doc/Documentation/arm64/tagged-pointers.txt).
   * **Does not require redzones to detect buffer overflows**,
     but the buffer overflow detection is probabilistic, with roughly
-    `(2**TS-1)/(2**TS)` probability of catching a bug.
+    `1/(2**TS)` chance of missing a bug (6.25% or 0.39% with 4 and 8-bit TS
+    respectively).
   * **Does not require quarantine to detect heap-use-after-free,
     or stack-use-after-return**.
     The detection is similarly probabilistic.