A tricky business this, as there are plenty of factors to consider. Past results, as they sort of say, do not guarantee future performance and the seedings are, in any case, based on three campaigns, meaning some teams (like Ireland it might be argued) are not quite where they should be in the scheme of things.

Based on just the most recent World Cup qualifiers, however, the following might be considered the teams to really look out for ...

BEST CASE
Pot 1: Both Bosnia Herzegovina and Greece are going to the World Cup after finishing on 25 points in Group G, but the absence of a big beast and the dubious quality of the group's lesser lights - Slovakia, Latvia, Lithuania and Liechtenstein - suggest they may have been fortunate to both be top seeds this time. England are a different proposition but Aiden McGeady says he would fancy a competitive crack at them and others in the squad just might agree.
Pot 3: Norway have some decent players but just 12 points from 10 games to finish behind Switzerland, Iceland and Slovenia in Group does not seem all that awe inspiring.
Pot 4: Estonia probably get the vote here after taking just seven points - six of them from wins over Andorra - from 10 games in a group that also included the Dutch, Romanians, Hungarians and Turks.
Pot 5: A couple of possibilities here but Lithuania might be the best, or worst, of them with 11 points from 10 games looking modest enough really given that nine came from their games with Latvia and Liechtenstein with only the draws against Slovakia suggesting any potential cause for concern.
Pot 6: At this level we should, of course, be expecting to beat any prospective opponents but Andorra and San Marino have a reassuring record of failure, including, whatever about the odd scare, against Ireland.

WORST CASE
Pot 1: Take your pick from Spain, Germany and the Netherlands . . . none would look too promising as a top seed from Ireland's perspective and memories of the humiliating defeat by the current champions in Poland as well as the home drubbing by Joachim Löw's men a few months late are still likely to be a little raw.
Pot 3: The Romanians are one of the lowest ranked sides amongst the third seeds but second place to the Netherlands in a group that also included Hungary and Turkey before a 4-2 aggregate defeat by Greece in the play-offs suggests they are an improving team.
Pot 4: Having only arrived on the scene relatively recently, the Montenegrins are still climbing the international ladder really and having held Ireland home and away a few years back, they comfortably beat Poland into fourth place this time thanks, in part, to a home draw with England and a win in Ukraine.
Pot 5: Iceland's shock second place finish to the Swiss in group E certainly suggests we would do well to steer clear of them while the derby nature of games against Northern Ireland would be a potential concern too.
Pot 6: They might not be up to much Luxembourg put the Dutch out of the competition over two legs in 1964 and even now, the six points from 10 games they took from a group that included Russia, Portugal, Israel, Azerbaijan and Northern Ireland last time out is not what you want in your minnows.