The times i remember seeing them do it (not to say these are the only times) is usually opening rounds where there is a lot "feeling out" and not much activity either way or in a final round if there are two fighter desperate tired fighters just sluggin away at each other for the last 45 sec or so towards the end of the round where there is no clear cut winner on a close fight. I've almost never seen the actual scorecards read 10-10 rounds since the judges are usually paying more attention not trying to commentate and do a bunch of other crap....