the bowline has worked loose on me during long routes, however the 「improved bowline 」 is something i use when i am sport climbing and falling off is more frequent.
称人结在我爬长路线曾经松开,而爬短路线且很常坠落时我会用改良版称人结。
the bowline is not only strong and secure but is easy to break loose later, even when pulled tight under a load.