Allow me to preface this question by stating that I am not a Big Bang denier.
I am reading the book A Universe from Nothing by Lawrence M. Krauss. In his book, he presents the following card as one piece of evidence for the Big Bang:
Apparently, the boxes outline the predicted abundance of each element in the universe, whilst the shaded areas represent measured abundances.
This may just be because I'm a (student) mathematician, but this seems like extremely poor and unconvincing evidence on the part of physicists. The only prediction that is convincing is that of deuterium; the other predictions seem to be horribly inaccurate.
As I stated, this is obviously only one of many pieces of evidence for the Big Bang. However, without considering these other pieces of evidence, it seems that physicists regard this specific piece of evidence as being in itself extremely convincing. As such, I wonder what it is that I'm misunderstanding? Am I interpreting this incorrectly? I realise that absolute proofs exist only in mathematics, but these predictions (excluding deuterium) seem surprisingly bad.
Sean Lake commented on what seems to be a graph with much more accurate measurements: http://www.astro.ucla.edu/~wright/BBNS.html.