Thanks for the suggestions - it is very helpful. I have access to another newer machine (which hopefully should be faster - I'm not convinced that it actually is though) and will give it a go on that. I have also made a shorter version of the sheet where I have taken out the last 6-7 weeks of the season to halve the number of games. With that number of games and only working off of 199 teams (I didn't have access to all of the relevant games at the time and the other 540 teams so it would have been less "game" lines) it took standard solver about 45 minutes to "solve" a similar problem.

Re: changing the algorithm - I totally get the point but don't think it is a viable option (I had trouble enough with this one - basically I struggle with the maths but get processes, I have been looking at this on and off for a couple of months and only worked out this week I had two columns the wrong way round which is why it hadn't converged up and until now). Usually I use Solver to do this kind of thing, but with 739 teams (and hence variables) I am above the variable limit, and the other way that I have for doing this by matrix's (it would work in a similar way and get a similar result) would be awkward (I struggled to build a 32x32 matrix - 739x739 would be very time consuming).

Thanks for the suggestions though and it's good to get a feeling of how quickly other people's iterations go. I suspect my laptop may be a touch cranky and old.