What is the best knot to join ropes of different sizes?

Double Sheet Bend ranks first (good field fit, 76%). Essentially level with Sheet Bend on weighted field fit (Good vs Good). Treat them as the same answer and choose on the tradeoff

And with cold, wet hands?

Sheet Bend moves to first (75%).

Sheet Bend moves to first (74%).

And with must come undone after load?

Double Sheet Bend still ranks first.

And with first time tying it?

Double Sheet Bend still ranks first.

Best knot to join ropes of different sizes

A thin rope onto a thick one. The bends that work for equal ropes start to capsize or slip when one side is much bigger.

Ranks first

Double Sheet Bend

Good field fit · 76% · 28 ruled out first

Why it wins

·Essentially level with Sheet Bend on weighted field fit (Good vs Good). Treat them as the same answer and choose on the tradeoff
·The mismatch join — two turns of the thin rope
·Same tail-side rule as a sheet bend
·Strong connection-job fit (96)

Watch for

!Only one turn taken around a much thicker bight
!Bight formed in the thinner rope
!Tails finish on opposite sides of the knot

How to tie it Run it with your conditions

Also in the running

02Sheet BendFast join of two similar ropes75%

Pick Sheet Bend instead Double Sheet Bend leads on connection-job fit (96 vs 84) and diameter relationship (82 vs 62). Sheet Bend still holds an edge on retie speed and field tieability.

What changes the answer

The same question with one condition added. Each row is its own engine run.

Cold, wet hands→ Sheet Bend
Low light→ Sheet Bend
Must come undone after loadHolds
First time tying itHolds

How sure this is

Moderate confidence: the order is sound, but the top few are close enough that your own conditions can reorder them.

28 of 30 modelled connections were ruled out by hard constraints before anything was ranked. A knot that fails a constraint is never scored, however strong it is elsewhere.

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