By Jonathan Agnew BBC cricket correspondent

Have I been lucky enough to have seen the greatest innings of all time?

I wish I could answer that question with absolute certainty.

But when one considers all of the pressure in the background to Brian Lara's extraordinary achievement, it would be very hard to argue against it.

For the last month, Lara - and his team - have taken the fiercest of criticism, ranging from their lack of discipline to doubts about their ability.

Lara was as thrilled as his fans after reclaiming the world record

Lara's captaincy has been called into question to such an extent that, before the second day of this Test match, it seemed inevitable he would be sacked at the end of the series.

Somehow Lara was able to block out all of this from his mind, and concentrate so single-mindedly that he was able to bat for 13 hours without giving a single chance.

It was a typical Lara innings in which he simply milked the bowling with well-placed strokes.

Only rarely did he unleash anything especially adventurous - he scores so quickly and easily that he does not need to take chances and, as his seven double and two triple centuries illustrate, this is a man who is supremely focussed.

The burning questions are, firstly, what affect will this tremendous feat have on the morale of West Indian cricket lovers and, secondly, will it ensure that Lara retains the captaincy?

Certainly, St Johns was a happy place to be - and the island of Trinidad will be celebrating wildly.

It would be foolish, though, if this great innings had any influence at all on the selectors' decision about the leadership - whatever that decision might be.

Lara is a great batsman - that has never been in doubt.

However, if the West Indian selectors believe there is a better captain in waiting, they should do the right thing before the series against Bangladesh begins in May.

There are some West Indian followers who felt that Lara should have declared at lunchtime - or even before.

It is always difficult to judge the timing of a declaration, especially when the captain is making a huge score, or on the verge of a personal landmark - but I felt Lara was correct this time.

This pitch is so flat that it is probably only through the pressure of chasing such an enormous score that England's top order was blown away before they had posted 100 runs.

It is a sobering thought that England have to aggregate 420 runs in their two innings merely to avoid their heaviest defeat in history.