West Ham: David Moyes will now realise the size of his task - Mark Lawrenson

David Moyes will have learned an awful lot about West Ham after their defeat at Watford in his first game in charge, and not much of it was good.

Off the field, there are more problems. The supporters are completely disenchanted, as was made clear from their banners and chants at Vicarage Road, although their anger was not directed at him.

The defeat meant West Ham stay in the bottom three and the only positive for Moyes was that, despite a poor performance, his side still managed to create some very good chances, and should have scored at least two goals.

But that should not mask the fact Watford fully deserved their win. The Hornets completely dominated the game and, at times, things were far, far too easy for them.

Hammers stay deep but leave big gaps

In the first half in particular, West Ham were too deep and too narrow, with and without the ball.

Their defence was given no protection at all out wide, and Watford found it far too easy in those areas.

That was not because West Ham's midfielders were too attack-minded, because they offered next to nothing going forward for the first 30 minutes or so.

West Ham's right side was a good example of that. Marko Arnautovic put in one good cross in the second half, which Cheikhou Kouyate wasted, but otherwise he contributed little in defence or attack.

It was not down to lack of effort - the 115.6km that the West Ham team covered collectively over the 90 minutes was the most distance they have managed in a Premier League game this season.

But there were still times when it appeared Watford had an extra man.

West Ham sat deep, initially, because I think Moyes was intent on making things as difficult as possible for the home side.

But it did not work. They invited Watford on to them, but still conceded far too much space in key areas and left gaps all over the pitch - without having a way to break out effectively.

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Carroll left isolated up front

Because they were so deep, West Ham took a long time to threaten at the other end too.

When he finally got a decent delivery, just before half-time, Andy Carroll almost scored - but for too long he was given nothing to work with in front of goal.

The balls played up to him were often hopeful and poor, but he had no team-mates anywhere near him anyway, even if he did get on the end of them.

Instead he always had at least two Watford defenders around him and, because he was so isolated, the Hornets always won the ball back quickly - and launched another attack themselves.

If Javier Hernandez had been fit and available to play off Carroll, then that would have made a difference, but solving the problem is not as simple as that.

Of course playing with two up front would make the Hammers more of a threat, but can they do that without becoming even more open at the back?

I am not sure. They already have the worst defensive record in the Premier League this season and, whatever shape Moyes decides on, I think he will be trying to put that right first.

Fans unrest could work in Moyes' favour

Moyes' first home game, against Leicester on Friday night, is going to be another big moment for him.

From what I saw and heard at Vicarage Road, the atmosphere at London Stadium is not going to be a positive one.

The West Ham supporters are clearly angry and disillusioned with the club's owners, and some of the players too.

Their chants about how they will be playing Millwall in nine months show how bad they think things are right now.

That might actually work in Moyes' favour, though, because if he can give them a glimmer of hope then they will really get behind him.

And, whatever the supporters think of the owners, I think they will back Moyes in the transfer market when the window opens in January.

Moyes probably already had a good idea of where things needed to improve before Sunday's game, but he will know far more now.

It is going to take time to get his players fit, because many of them have been away on international duty for most of the time he has been at the club.

The defensive stability Moyes wants will not just happen overnight either, and he needs to find a way of balancing it with their attacking threat.

I think he knew he had a big job on his hands anyway, but now he will know how much work he has to do in every area of his team.

Mark Lawrenson was speaking to BBC Sport's Chris Bevan.