Well, a few things. First is, if you alt-tab out of game for a minute, then come back, check your ping, its really low, then goes up.
BUT, and a big but, a lot of people run standard rates, or even worse up thier rate to say 20000, but leave thier cmd and update default, ie 20/30 or whatever. This will give an artificially low ping. However it is a scorebaord ping, if they check netgraph u can see its not really that.
Another way, if you change your cmdrate to 5, or 0, you will get a ping of 5 solid on the scorebaord. Its not really 5, it just says that.
All this cna make you slightly harder to hit, but tbh I reckon its all a bit hyped, and ignore it, unless Im in a match, in which case I say
OMG FFS RATE HACKING MOTHERFUCKERS JESUS PLAY US ON OUR SERVER YOU BASTARDS!!!
But then so does everyone else ....