It has been discussed elsewhere. Its basically down to a win and a draw against Belgium, other wins against the might of Cyprus (2-1) Andorra (2-1) Isreal (3-0) and a draw against Bosnia. Prior to that they lost 6 out of 10 qualifying matches to not get to Brazil 2014.
How Belgium stay at 2 when they can only draw and lose against Wales is beyond me.
Ted Rogers must have devised the formula and should they go higher than 9 in the rankings then a dusty bin will be wheeling its way to Cardiff!
I'm not anti Wales and I'm glad about their recent success and I hope that they qualify for France. Nothing will please me more than to watch Dave Edwards pit his wits against Europe's best next summer considering some will tell you that he's not fit for League One football.
It's also because they haven't played many friendlies. You don't lose points for playing them but the weighting is very low, (especially when as England have done you don't actually win the friendlies), so it brings down your average.