Hello! How can you possible tie a figure of eight knot in a taut jib sheet stretched between the block and the foul turned winch?!

As part of the playground design, we've included a cargo net which kids can climb on. Of course, we have to make the cargo net ourselves. So I've got a dozen Firefox tabs open, all to various knot/net-tying sites. My favorite is Animated Knots by Grog, which contains such impassioned gems as this:

"History: The Rolling Hitch has a complicated history. It is linked to similar knots named the Magner's or Magnus Hitch. It is all too commonly described without the second turn being 'tucked above' turn one - even when being tied to rope. This is unfortunate. Ashley clearly describes both methods and stresses that the version used when tying rope to rope should include this tucked up second turn (ABOK # 1734, 1735, p 298). Many scouting websites show it without this tuck. The error of using the wrong technique is illustrated by cautionary statements which often follow the description, e.g.,

'... Tip. When adjustments are complete, lock the rolling hitch into place by using a stop knot such as a Figure of Eight in the first rope, below the Rolling hitch, to stop it slipping...'

Hello! Tie it correctly and it doesn't slip under load. And, how can you possibly tie a figure of eight knot in a taut jib sheet stretched between the block and the foul turned winch?"