Best Global Universities

I was shocked to see that the University of Washington in Seattle was ranked the 7th best university in the world.  At least according to some recently released rankings.  It appeared above Cambridge (which was 8th), but below Oxford (which was 5th).  I wouldn't trust the objectivity of these rankings, since they seem to have come from some US media outlet - and so other than Oxford and Cambridge the top 10 is dominated by US universities (with Harvard as #1).  I never really think of the UW as a top tier university, but I guess it's up there.  I was kind of curious to see where my alma mater - University of Bath - ranked, and it came in at a lowly #412.  Which is the #35 best university in the UK.  Has the University of Bath gone really downhill since I went there?  I'm sure it was considered a top 10 UK university in my time.  And in fact some quick internet research does reveal that most current UK rankings have it around the #8-#10 range, which is more like I would expect.  Jeez, the criteria that they use to come up with these US rankings must be wildly different.  When I look at the subject matter rankings then it is ranked a bit higher in math(s) at #122.  Still, does that mean that there are 121 universities in the world that I could have got a better education at?  Crikey.  Mind you, I don't think it really mattered where I studied mathematics - it was a subject that I was good at but which I was never really passionate about.  And, if I'm going to be honest, studying it is one of the biggest regrets in my life.