I don't see a capitalist-workers connection. There isn't enough in the quote to get that idea. It seems to me a simple statement about how people can do harm and not know it or not care about the harm they cause. Couldn't it also be about meat eaters and the harm they do?

In a captialist / worker scenario, I would be looking for an exploitation of the means of production, or a similar relationship, which I don't see here because the frogs have no value to the boys. In my opinion, it's more about being aware of the consequences of your actions - for you it's a game, but for lower-order life it's an ordeal. You have the powercapacity/conscience/sentient ability to make life-or-death decisions, so you should make them coonsiderately. On the other hand, maybe I'm completely wrong ;)

Your interpretation of this sentence is right. I didn't read Bion, so I can't be sure, but I do think the 'sport' can be referring to any kind of competition, and then the boys would be the powerful actors in capitalism, and the frogs the poor workers suffering from their actions. Hard to tell since at the time Bion (325-c. 250 BC) wrote that, capitalism didn't exist. To be sure, I guess it is needed to read the original text, and compare it with today's capitalism. Interesting question, I'd like to know what others are going to say about it.

I think Bion wanted to emphasize how important it is to weight all consequences of our decisions and acts (in the limits of our imagination) and also to try to see an action from the point of view of the one at the other end. This in order to decrease the possibility of tragic situations. Very interesting that he talked about a game (for the boys), not about men hunting for food. Several years ago some boys here in Italy did a 'game' that was throwing stones from bridges to cars passing below; it happened several times. Death was the result; Bion's thought should be incorporated into grammar's school curricula! I never heard about Bion, thanks for letting me know.