The fact is..even when the roof is open most of teh ground is shaded anyway, especially during winter when the sun is low. So apart from causing a shocking sunny square patch in the middle of the ground for the 1st half, theres no benefit in opening it. My one proviso would be install some extracti...

I voted for "just out of form". Give him time, he'll come good.

He was a slow starter a couple of years ago, too, iirc.