So far, so good but the real tests will come later for this England

When Andrew Strauss discussed the summer ahead, the word "improvement" came up regularly in conversation. The captain's first century since November 2010 underpinned an authoritative batting performance but England's return to form merely proved what most suspected: with pace on the ball, this top five is as powerful as any.

We will learn later in the summer how England cope with South Africa's fearsome attack. While the difficulties experienced in the winter seemed far away in chilly St John's Wood yesterday, the renewed assurance displayed by the home team is no guide to how they might play when they must face subcontinental conditions again later this year. Winning in India has been described as "the final frontier" by Strauss; dominating the West Indies bowling leaves them no closer to conquering it.

Here is England's Catch-22. They are experts in their own country, where they have not lost a Test series since South Africa claimed the 2-1 victory four years ago that ended Michael Vaughan's reign as captain. Serious doubts remain about their ability to succeed in Asia, yet if these batsmen continue to score heavily during the English summer, how can they be denied a place in the group for the winter tour of India that might define how this team is judged by history?

These questions will have to be answered when the leaves start to fall. The news of the day is that with midsummer a month away, Strauss has regained a firm grip on his place at the top of the order with a perfectly-paced innings that belied the nerves he must have been feeling.

There were few mistakes, although he was dropped at first slip off a Fidel Edwards no-ball on 95, and few displays of agitation. The shot selection was judicious, the footwork assertive and the strokeplay crisp; an on-drive off Kemar Roach that cruised to the boundary in front of the pavilion was probably the best shot of the lot.

Strauss joined Kevin Pietersen, Ken Barrington and Graham Gooch on 20 Test centuries, two adrift of Wally Hammond, Geoff Boycott and Colin Cowdrey. As Strauss jogged forward to celebrate his achievement, Pietersen enfolded his captain in a bear hug that looked as though it could break a couple of ribs. It would be fair to say KP has never been a man to embrace understatement.

While Pietersen likes to dazzle, Jonathan Trott is content with a low-watt glow. It is a measure of Trott's excellence since he came into the Test team three years ago that his 10th Test half-century faded almost completely into the background.

Trott's idiosyncrasies, such as the painstaking way in which he takes guard, are too often derided, as is the one-paced nature of his batting. How many teams in world cricket would turn away a man who has seven centuries from 29 Tests at an average of nearly 53?

It was a rare false shot that cost Trott his wicket, but his record in Tests at Lord's is astonishing. In his first two Tests here, he scored a double-century against Bangladesh and took a match-turning hundred from Pakistan in the tainted Test of August 2010. This was the Warwickshire player's third 50 in as many Tests here, and his average for England in five-day cricket at the venue is now 82.

This series is a tricky one for England. Three convincing victories will be accepted as the minimum; anything less as a cause for worry with South Africa arriving in July. So far, so good. England know, however, that tougher assessments of their qualities will come against other teams and in other lands.