Steve Waugh feels the upcoming Ashes will be highly competitive and it is too close to pick a winner amongst the two sides as Australia and England begin their quest for supremacy in Birmingham on August 1.
Australia are still in search of their maiden Ashes win away from home ever since they triumphed under Waugh's leadership back in 2001.
Waugh said the contest was "50-50" considering the quality and bench strength of the two teams.
"I really believe it's a big ask for the fast bowlers on both sides to play five Tests in six weeks and that could have a big impact on the whole series, so for instance Jimmy Anderson gets injured, or Mitchell Starc gets injured for us, it could really affect the line-up.
"Depth in the squad will be important but I honestly think if I was a betting man I wouldn't back either side because I don't know who's going to win. It's going to be that even. I think it's going to be a fantastic series."
Waugh is currently mentoring the Australians for the five-Test series and was flummoxed by the fact his country had not triumphed on English soil in 18 years.
"We've come up against some really good England sides in those last 18 years. We've had some tight series and moments when we could have won the series, probably a bit like the other way round for England in that period where they lost a lot."
England will be buoyed by their historic World Cup victory achieved two weeks ago at Lord's but Waugh opined one-day cricket was "irrelevant" to the outcome of the Ashes which is a different ball game altogether.
"One-day cricket is irrelevant to Test cricket," he said. "They're different teams, different captains. It's a different sport really. If you compare Test cricket and one-day cricket you're almost not playing the same sport. It's played in a totally different way.
"England will say it's important for everyone and sure, if you win that's great but when it comes to the first Test at Edgbaston it's not going to matter what happened in the one-day World Cup."
Thursday's match is scheduled to take place at Edgbaston, a venue where England have remained unbeaten from 2008 onwards, however, Waugh said this would not play on the minds of his players.
"I've won there in Ashes contests," he said. "I think if you start believing something and building it up it becomes true but in my mind it shouldn't be an issue."
The 54-year-old claimed he expected a hostile reception from the English crowd for the Australian duo of Steve Smith and David Warner, resembling the treatment they were given during the recently concluded showpiece event.
Waugh believed Australia had undergone a transformation since that low point and affirmed his belief in Tim Paine's leadership credentials.
"Australia had to reset and revisit a few things, which is unfortunate because of what happened. I think they're in good shape. (Test captain) Tim Paine's done a really good job and he's a good leader. Hopefully you'll still see the Australian team play the Aussie way on the field.
"We've got to be combative and play in a positive frame of mind because that's the way we play our cricket."
"Things culminated in Cape Town and were out of control there and there were a couple of ordinary series between different sides... It did get to the point when it was over the top and something needed to be done so unfortunately for the guys involved they were the ones that paid the price," he added.
"The good thing is now that everyone knows where the line is and you can't cross that line. It was great for kids too because kids all round the world saw that, particularly in Australia, and it was a good lesson as to what's right and wrong."