And even if England win all three World Cup warm-up games next month, their success ratio during the four years between tournaments will remain at 50%.
Such inconsistency means the world champions are not rated in most quarters as serious contenders, certainly when compared alongside fancied semi-finalists New Zealand, South Africa, Australia and France.
Vickery, England's World Cup captain, readily accepts that results suggest his squad has it all to do when they bid to emerge from a qualifying group that also includes two of their 2003 pool rivals, South Africa and Samoa.
However, he insists there is cause for optimism.
"If you were a betting person and you analysed results, then it is not a particularly unfair comment,' he said, responding to the view that England might already be World Cup write-offs.
""We have not had a great couple of years, but everyone involved is working and striving to get back to the top of world rugby.
"We would all like it to happen overnight, but it doesn't happen that way.
"But we have certainly got a lot of great players and a good coaching set-up in place. Hopefully, we can produce it at the World Cup.
"Everyone will be waiting with their guillotines, and if it doesn't work out, they will give us a good chopping.'
England's extended World Cup training squad has spent the last week being put through its paces in scorching temperatures on the Algarve as the tournament build-up gathers pace.
The opening warm-up game against Wales at Twickenham is just four weeks away, and 10 days after that England head coach Brian Ashton will name his 30-man World Cup squad, with Vickery admitting: "The clock is ticking.
"I don't want to be part of something that is not successful.
"But you cannot sit in your room at night solely worrying about the negatives that are going around. We've got to keep trying to progress as fast as we can."