Gatland:'The closest World Cup ever'
Wales are drawn in the so-called "Pool of death," alongside England, Australia, Fiji and Uruguay in Pool A.
Gatland said: "I believe this is going to be the closest World Cup that we've potentially had.
"There are a number of teams that just need a bit of luck, and get through their pool stages and everyone there has got an opportunity.
"We found that in 2011, getting through the pool stages to the quarterfinals – and we know how close we came to making the final.
"I think there are seven or eight teams that would fancy themselves through to the quarter-finals – everything's to play for."
Gatland added that the showing by the northern hemisphere teams against their southern hemisphere counterparts in last season's end-of-year tours – allied by some expansive rugby in the Six Nations – was "a real positive".
With only two teams automatically qualifying for the quarterfinals, it means that two teams from four ranked in the top 10 in the world will not make it out of Pool A.
"You don't look too far ahead, you look at one game at a time," insisted Gatland, who oversaw Wales to a nail-biting semifinal defeat to France in the last World Cup.
"Everyone's talking about how the pool may be decided on points difference. I don't think it will be decided on points difference.
"I think we're up against it in that regard, given the experience we had in the Six Nations," he said in reference to the staggered final round of matches last season."
Wales racked up a big score against Italy before Ireland ran away with the title in full knowledge of what they had to score against Scotland.
Wales kick off their campaign against Uruguay at the Millennium Stadium on Saturday – Gatland stressed that the emphasis was on quality execution.
"Other teams are going to know the permutations before we do, so it's about making sure we go and have a good performance.
Then concentrate on that – and really focus on England, that's massive for us," the New Zealander added.
"Other teams are going to be at much more of an advantage than us going into the last couple of days – potentially the last round of games – to be able to potentially take advantage if there does come a points differential situation."
The former hooker said he didn't have an optimal score in his head for the Uruguay match.
"I don't care about the score, I just want to play well and win," he said.
Gatland also said that prop Samson Lee and fullback Liam Williams would both get a run against Uruguay after slowly coming back from injury.
"They need game time, but probably not 80 minutes," he said.
"It's a bit of mix and match about putting a strong team out – still thinking about potential points difference – and going out there and giving a good performance, while trying to get as much points as we possibly can.
"That's not disrespecting Uruguay in any way, because they're going to be tough.
"It's their first game and they're going to bring everything to the table as well."
Source: Agence France-Presse
