Betting the same or opposite as last will always, always in the long run get you to the same exact place at the end off the rainbow, every time collectively.
You could also toss a coin in order to decide, Head for Banker and Tail for Player.
I remember when I was playing Blackjack at Casino De La Vale, near the Italian Alps, I was wondering at the 2nd floor, where the table games are located, carefully estimating my opponent by looking, not on results, but his face!
I looked at a middle forties man with dark fair goatee and hair, suddenly has hit me;
"I cannot be more unlucky than this guy!"
I sat down and the dealer rolled his sleeves up, I was the only person at the table, while the game begun to unfold I was stacking piles of chips in front of me, from the left to the right each pile had 1 chip more than the previous.
From the corner of my right eye I saw a pit boss and a floor manager looking over my shoulders and discussing silently, suddenly a bunch of Asian origin tourists came to the table, I was doing well and news get around fast...
A charming Chinese (?) girl at her early thirties sat next to me, after a few hands I told her:
"why don't you take advantage of the special bet for Blackjack?"
She did so immediately and won 18 times her special bet, she looked at me and said:
"how did you know?!", while chuckling hilariously.
I've draw a generous portion of smoke and replied: "I didn't", while blowing my Cohiba cigar at her face.
Players kept following my hands as the dealer changed and things took slowly but steadily the downturn, I thought:
"Time to shake my Submariner while rolling the dice at the Craps table", but this is another story...