yo latrucino,
yup I've had the best luck nailin down doubles...good payouts on 'em too...my best was $429 on a straight/box double here in CA.
to TRY to predict when they will strike, I look at past draw data, see how many skips are between doubles striking. also try to gauge how often double streaks come up.
another reason why I will sometimes play doubles is that my system indicates certain digits numerous times, and they are lined up as likely candidates in 2 or even all 3 of the positions.
later,
blitzed