Overhand- v. figure-8 on a bight

Which do you use, and why? As I understand it, both are acceptable methods of creating a strong loop in the middle of rope (or webbing or cord). The use cases I had in mind are creating a master point in an anchor, rappel extension using a sling, or clipping to your belay loop to lower off after cleaning an anchor in single pitch settings . . . I'm sure there are more. I'm wondering why folks choose one over the other, and when. The overhand uses less material . . . any other advantages? Are there situations where a figure-8 is strongly preferred? Thanks!

I use a figure-8 over an overhand when I think the overhand might be hard to untie.

for a dyneema sling master point, i add as many wraps as needed to out the slack (think a figure 8, but keep wrapping around). with the rope, almost always an overhand on a bight because it's strong and quick.

Nate H wrote: Which do you use, and why? As I understand it, both are acceptable methods of creating a strong loop in the middle of rope (or webbing or cord). The use cases I had in mind are creating a master point in an anchor, rappel extension using a sling, or clipping to your belay loop to lower off after cleaning an anchor in single pitch settings . . . I'm sure there are more. I'm wondering why folks choose one over the other, and when. The overhand uses less material . . . any other advantages? Are there situations where a figure-8 is strongly preferred? Thanks!

Figure 8 is easier to untie after loading.

As ScoJo said, an overhand will be harder to untie, especially with Dyneema after being weighted. With a cordalette, the overhand will untie easily when used as a masterpoint.

Even better to untie Dyneema is a Figure 9 (extra half wrap).

Alpine butterfly.

master gumby wrote: Alpine butterfly.

Was wondering about this in similar comparison. Specifically, when multiple people are on a rope in alpine or traverse situations, why a butterfly over a figure 8 on a bight? 

Much has already been said, ease of untying and material bulk considerations, although for joining two ropes together, their "flat" cousins have some preferences.  The flat overhand is preferred and I believe in some ways has been shown to be safer than the flat 8 (not the flemmish bend).  

Jay Dee wrote:

Was wondering about this in similar comparison. Specifically, when multiple people are on a rope in alpine or traverse situations, why a butterfly over a figure 8 on a bight? 

load the knot in either direction.

The overhand on a bight and figure 8 on a bight are both pretty hard to untie compared to other knots. The alpine butterfly is going to be much, much easier to untie than either knot, and if the situation allows you to use a clove hitch, that will be even easier to untie.

The advantage of an overhand on a bight is that it's fast and easy to tie, and while it's rarely ideal once tied, it's a good-enough knot for creating a midline loop in most situations.

The figure 8 on a bight is good as a faster way to tie a figure 8 follow-through near the end of a strand. I can't imagine using it as a midline knot unless I didn't know a lot of other knots. Butterfly? Clove? Directional figure 8? I'd choose one of these knots over the figure 8 on a bight in any midline situation I can think of.

Rope Byrne wrote:

load the knot in either direction.

So to be clear, if someone in line before or after you fell the force from that side, or both sides together, could cause the knot to fail? 

Jay Dee wrote:

So to be clear, if someone in line before or after you fell the force from that side, or both sides together, could cause the knot to fail? 

Overhands and figures of eight (heh) can roll when you pull their tails apart, some more than others. ABK don't.

Thanks for clarifying

Thanks all!

J D wrote:

So to be clear, if someone in line before or after you fell the force from that side, or both sides together, could cause the knot to fail? 

No. Since you are clipped or tied into the bight of whatever knot you were using, it could not collapse. With huge sustained loads and/or poor dressing, a figure-eight could "roll" on itself if loaded from both sides. But again, the middle person prevents that from causing a failure (as opposed to for example when joining ropes). In theory, if person 1 falls into a crevasse, person 3 arrests the fall, and person 2 unclips from the bight to assist in setting up an anchor, THEN the knot could roll and produce some extension. But this is unlikely since the load is now only body-weight and the knot already tight.

In all practical applications, except possibly for joining ropes, there is no relevant difference between a fig-8 on a bight, an overhand on a bight, or a butterfly. The butterfly is the prettiest knot of them all, and most difficult to master. The overhand is most simple but sometimes a little harder to untie. Cheers! :-)

For a master point on a two point bolted anchor, an alpine butterfly. Easy to untie. Impress your friends.