India already disappointed many in last 2 matches.
I know SA as of now is very confident and only one match is enough for India to come back and it can happen at any time.
Yes what you said is correct as of now Indian team need only one win which can boost their self confidence and India players once gain that confidence then no one can defeat them in home grounds but SA's many players are playing in IPL so they also more familiar with indian grounds and taking the advantage now. Any way this match very difficult to guess the winner.
Any way this India and SA match not easy to predict for betting so better just enjoy the match instead worrying on betting.
For me betting is just for fun, the enjoyment of the sport is always first.
So therefore I bet for fun and with small amounts.