The planetary positions only give indications. You cannot say that what is predicted will happen 100%. They only give an indication because there is always an element of "grace" that can change anything, anywhere, anytime.
This is the reason spirituality or sadhana (spiritual practices) are a step higher than the knowledge of astrology. Astrology is knowledge - it is necessary to know it. However, there is something more remedial. Sadhana, satsang (company of truth), devotion, are all remedial measures that help.
Astrological predictions are like weather forecasts. There is always a probability factor. The remedy for malefic effects is devotion and seva (service).
