Grrrr – why didn’t you rise sourdough?

Twice now I’ve made my sourdough recipe – same one I’ve been making since June this year and twice now (in a row) it didn’t prove the last time.

I didn’t do anything different.
Why Oh Why?
Maybe it was a bit hungry when I first started.  Maybe it was left a little too long on the first prove.
Do these things matter?
Ahhh research project just presented itself.
I just want bread

So many recipes, which one is the best?

It occurred to me today while trawling for soda bread recipes that I really have little way of discovering which ones are worthwhile baking.

How does one decide?
How do you choose between one recipe and another?
Share your tips with others – comment them here!