[Kevin Sevcik]

I think the meaning of a negative result out of the formula is fairly obvious. The result of the formula is clearly stated as the time on the match countdown clock by which you need to get a ball back on the field. The countdown stops at 0, so it will never reach a negative number, so those balls don't need to be returned to the field. It's the only result that makes sense. The only other options are to force teams to return balls after the match ends, which is pointless and delaying, or to clip the formula result at 0, which means you get penalized for that last second goal you made that you literally had no time to return to the field.

So I think the smart move is to have human players hold any balls scored in the last 11 seconds of a match. Or possibly more if you've got a big backlog.