I thought you only get gold when all the portals are killed, so playing out the whole 20minutes would just give you the point. And as for the special thing, just don't use a special for like 100 rounds (sometimes others will, but oh well), and you'll see that sometimes you get a wack load of spinners, and sometimes not. The same is true with using the specials. But I find that the longer a portal lives (lack opf attacking and such) is usually when there are the greatest amount of spinners (may sound obvious but w/e).