Alec Stewart: Pietersen should be making bigger scores

Pietersen has amassed 16 centuries in 93 Test innings but has eclipsed the 200-mark just once, smashing 226 against the West Indies two years ago.

With the Ashes series beginning in Cardiff on Wednesday, Stewart believes Pietersen will continue to thrive amid the pressure of trying to topple Australia.

But he has challenged the 29-year-old to emulate West Indies great Brian Lara by producing more double centuries once he has entered three figures.

"Pietersen is the best player in the world", Stewart said. "He's the first batting genius since Brian Lara.

"But what I want to see him do is push on and get greater scores - not just 100 to 150, but 200 to 250. That's what Lara used to do and Kevin is talented enough to do the same.

"Pietersen will be loving this series. The bigger the stage the better he performs. He's a world-class performer."

Alongside Pietersen, Stewart expects strike bowler James Anderson to emerge as England's key player this summer.

"James will have a big, big series. He has grown in confidence since being given the role of number one lead bowler," he said.

"He has grabbed it with both hands. He has got a grooved action - a repetitive action - and has overcome his injury problems.

"He will be crucial. If he and Pietersen do well I think we'll win the Ashes."

Australia are favourites to retain the Ashes they won with a 5-0 series whitewash in the winter of 2006-07.

Stewart, however, believes the recent success against the West Indies is evidence England are heading in the right direction after negotiating a difficult spell.

"It will be tight but I'm backing England to win by one Test match. They have made strides forwards," he said.

"The Andrew Strauss and Andy Flower partnership has gelled very nicely. The squad has responded well to that type of leadership.

"I'm getting vibes that it's a very good squad environment at the moment. England have got it right to beat Australia. And they're playing nice cricket. They annihilated the West Indies, although the conditions were wintry, and I saw signs that this has the making of a very good side.

"Don't underestimate Australia. They are a fine side. Ricky Ponting is world class and they have enough top-class players to win.

"Australia are not the side of old - there's no Justin Langer, Matthew Hayden, Glenn McGrath, Shane Warne or Adam Gilchrist.

"But they still produce good players. Whether they have the strength in depth or experience of playing in England is questionable."