I was pointlessly poking around Wikipedia tonight and found this little gem.

If the hitch does not hold securely due to slickness of the standing line, an extra turn should be made around the line, with the end still tucked only under two.

If the hitching line has trouble gripping because it is relatively stiff, an extra turn should be made and the end tucked under it (which gives more thickness for the stiff rope to compress).

Interesting. I have been wanting to experiment with 4:2 vs 5:3 and with 12 vs 16 strand but decided to wait a few more days for my new rope.

We gave up on trying to correct wikipedia because someone comes after you and changes all up with some of the info being incorrect in the first place. People that have never seen a rope or used a figure 8 go there and change things just to demonstrate they can do it!

Them someone else comes later looking for info and reads some of that stuff and thinks it is correct just because it is posted on a Bulletin Board. You are better off reading stuff posted here or at TCC or at any of the Professional Arborist sites

About using 5/2 or 5/3 I personally use 4/2 most of time on my split tail ropes and it works fine for my weight. I have not used the Traditional system in a long time and now I mostly used a Distel or a Schwabisch prussic with a mini pulley instead. Moss has posted photos somewhere here before or look in his Flickr site.

Yup, the 5/2 sounds redundant, I can't see how it would be any more useful than the 4/2. Adding more wraps above a 4/2 to get a 5/2 or a 6/2 doesn't make much sense. 5/3 and 4/2 are standard Blake's configurations that work very well.

If a rope is stiff enough that it won't hold weight with a 5/3 or 4/2 then it's probable that the rope is not designed for "self-tied" or trad friction hitch tree climbing.

I do like the tip that mentions tucking the rope up through multiple wraps (more than 3) to allow a rope with not enough minimum bend radius (like a typical static rope) to grab. Nothing I'd do for day-to day climbing but could come in handy for an emergency. Definitely would want to test low first to see if it works as advertised.
-moss

Here's some weird griping about the Blake's 5/3...

http://www.treebuzz.com/forum/showflat.php?Cat=0&Number=152701&an=0&page=0#152701

That was JZ posting on Treebuzz about a 5/3 slipping. I've never seen a properly tied 5/3 not holding. It will hold even when set very loosely. The more typical problem with a Blakes is that it binds up after long hang times, the 5/3 does this less than the 4/2. The only adjustments I've ever had to make to a Blakes during a climb was to loosen it.

I think there's something missing from the picture. JZ would have to reproduce the problem and document (photo of the hitch and the TIP) to move the discussion forward. The rest of the thread is work climbers who rarely climb on a 5/3 and the rest who rarely climb on a Blakes.

The last comment by Mark Adams about the F8 on the bridge was interesting. I'd like to hear more about why that's no longer considered a useful knot for rescue. Clearly it's a mainstream convention in rec climbing. The question is should it be revisited to determine if it is actually useful or problematic.
-moss