Is Michael Vaughan a very decent batsman who had a brief spell in which he could do no wrong? Or is he a batsman of classical genius who has been unlucky with injuries and other matters beyond his control? A conundrum to wrestle with yesterday as I watched him make the top score of 106 in the England innings at Lord’s. The question had added spice because it seems that Vaughan doesn’t know the answer either.

Certainly he went into this match against New Zealand in urgent need of a score: a state he finds himself in more often than he would like. He had a poor winter, but then that’s the problem with captains. The team he led recovered from a dreadful Test match in New Zealand with victory in the series. Is that not sufficient?

It isn’t of course. And yesterday he played the innings of a man battling rather more than the opposition. There were moments of freedom and beauty, and few batsmen in the world do beauty better than Vaughan. But there were plenty of other moments when he seemed oppressed by care and caution - and the need for a personal rather than a corporate statement. With each low score he can hear the ever-louder murmuring of the critics.

At one stage, coming in at 121 for one, he seemed to have the idea of filling his boots and forcing a win. Daniel Vettori changed his mind with three quick wickets, leaving Vaughan to play an intriguing half-and-halfer of an innings: leaving the ball a lot, spending plenty of time off strike, looking for ones and twos. But every now and then he would make that profound genuflection, right knee kissing the turf, as the prettiest cover drive in England made its little hop over the boundary rope, a shot breaking out of a cautious innings like Superman leaving a phone box.

Vaughan had his time of perfection in the (losing) Ashes series of 2002-03 in Australia, in which he made three big hundreds and scored more than 600 runs. For this brief, blessed time the game was easy for him and it has not been quite the same since. Not for sustained periods, anyway. He became captain, you see. Now you should never ask a captain if captaincy affects his form with the bat. It only upsets him. The traditional form-dip of the newly appointed captain seems to be a particularly English affliction, reflecting our traditional veneration of leaders. Such concerns never seemed to trouble Mark Taylor or Steve Waugh or Ricky Ponting, of Australia. Vaughan was a great success as a captain, but the assured magic of those Australian days had gone.

Without ever hitting those heights as a batsman, he led England through an unbeaten 2004 and on to the Ashes summer of legend. Here, Vaughan made a single century, one in which, in successive balls, he was dropped and bowled off a no-ball. But the ultimate victory was England’s, and his. But that’s when the injuries began, especially the dodgy knee. He missed all of 2006, including the Ashes debacle that winter. Since he returned, the magic has been capricious, teasing, flirtatious. A glorious cover drive would appear, but nothing followed. There was a fabulous century against West Indies last summer and a pretty sorry winter to follow. And it’s a fact of batting, of all sport, that the magic periods never come for the asking, and are never more distant than when most urgently desired.

He reached his hundred yesterday - his eighteenth in Tests - with immense relief and a beautifully struck four off Vettori. It was an innings more remarkable for bloody-mindedness than beauty. Was this the day when the old genius was reclaimed? Or when the very decent batsman was reaffirmed?

This series against New Zealand represents one of those occasions in which the odds are in your favour and the only real pressure comes from your too-urgent need to cash in. As yesterday unfolded, some flow returned to Vaughan’s game. At the end, he knew that if his innings lacked that old Antipodean magic, it still had the considerable virtue of shutting everybody up. It’s not the same as batting like God, but it’ll do.