Rajyoga and key planet in astrology

Maharishi prashra who was the founder of astrology depicted about rajyoga in his famous scripture "Vrihat prasharhora shashtra".According to to him some houses and their lord made certain kind of combinations that brings prosperity,name and fame.How does this yoga made?, what is the impact of this to anybody?.Before we discuss about this let us know what is the meaning of term 'Yog'.A yog means when two or more than two things combined,a new thing comeout and in astrology when two or more then two houses or their lord meets that create rajyoga.It means that you have all the materialistic things.the lord of 1st.,5th.,9th. and 10th.in horoscope made this rajyoga.When both of them aspected or conjoin with each other then this rajyoga is made,it means that you have some certain kind of qualities and that will repay you according to their strength.Suppose your lagna lord is out of this range then you will not enjoy that rajyoga in real sense.This actually means if fifth,ninth or tenth lord combined or aspected by each other then this yoga is made,again you describe it that by birth you have some certain capabilities but if lagna lord is out from this range then you will not really enjoy that rajyoga.Actually first house recognise self and self is much important then other things,fifth house is our intelligence,ninth house is called destiny or dharma again means you have to abide some rules for success and tenth house means our karma or efforts and hence when both or any of them is not illplaced or hammed between malefic planets or not aspected by malefic planets then that rajyoga is enjoyable.Inspite of astrology you took this just like if somebody do something with intelligence and do that with full devotion and follow some basic rules then success will be waiting for you.What about the key planet, a key planet is just like a special quality which you have inside you and every lagna has one key planet( it means a positive energy inside you)which is the base of your success,it should also be free from evil impact by any other malefic planets and when this key planet conjoin with other good planets then this will ensure your success ratio.How we can calculate this,we have to study "Ududayapradeep" or "Laghuprashari" written by Maharishi Prashra.The seven planets in sequence play this role i.e Sun,Moon,Mars,Mercury,Jupiter,Venus and Satrun.Sun plays the role for aries and saggitarius lagna, moon plays for scorpeo lagna, mars for cancer and leo lagna, mercury for taurus and virgo lagna, jupiter for pisces lagna, venus for capricorn and aquarius lagna and abobe all satrun for libra lagna.The key planet in any horoscope if is well placed and aspected by lagna lord then prosperity,name and fame will surely be given to you and if fifth,ninth and tenth lord are also involved in this combination then you will do some miracles in your life.