obviously you don't know baseball either, or you would have substituted 'dugout' for 'shelter'.
No doubt you are correct, tsuwm - I was harking back to the good old days of the Second World War, when we all enjoyed the comradeship engendered by close proximity in constructions of pressed-iron covered in garden soil which were a fool-proof method of avoiding the bombs rained down on London by that nasty Mr. Hitler.
As to a "knowledge" of baseball - or cricket, for that matter - it is confined to having watched games being played. Indeed, I have played cricket, but only under duress and never with enjoyment.
I watched baseball over a period of about two months at some of the American Airforce bases in Northamptonshire,m which were acclaimed by those around me as being of reasonably high standard. I will admit to finding them better fun than cricket - but only marginally, and there was no beer !
