The Yosemite Finish — the Yosemite Tuck or the Euro Tuck — is a small tweak to a standard tie-in method. At its core, it’s a way of finishing a standard figure-eight follow-through knot used to tie into a climbing harness. The knot itself is already strong, simple, and time-tested. The Yosemite Finish doesn’t replace it; it just cleans it up a little bit and makes it mildly easier to untie.
After tying a normal figure-eight follow-through, the tail of the rope is threaded back alongside the knot and tucked neatly through the top loop. This pulls the tail parallel to the standing part, reducing the chance of the knot working itself loose and keeping everything compact. The result is a tidy knot that sits closer to the harness, doesn’t snag as easily, and looks like you know what you’re doing—always a bonus at the crag.
There is nothing wrong with the “classic Yosemite Finish” if you clip your belay device properly. If you clip the device improperly and clip the loop around your harness, instead of the belay loop and a leader takes a fall, the whole knot can invert and fail. This is rare, but a very important thing to understand.
So the classic style isn’t wrong. It just has a weakness if improperly used. But most climbing knots have a weakness if improperly used.
It should be noted that some of the old school harnesses like the original Black Diamond Bod Harness don’t have a belay loop. This is where one could get into trouble, by trying to make a belay loop with the tie-in loop and then trying to catch a lead fall on that. The best practice is not to use the inside of your tie-in to belay.
If this is of concern, it is possible to add an additional wrap around the running end of the rope before tucking the knot. This will decrease the likelihood of capsizing if a belay mistake is made.
In the end, the Yosemite Finish isn’t mandatory, magical, or mythical. It’s just a refinement. If this is a refinement you like, go ahead and use it. But be sure that your partners understand the knot and can check it adequately for you before you leave the ground…
–Jason D. Martin