When a sign is divided into three parts each of them constitute a drekkana. Jagannath Drekkana starts from Movable sign in trine to the sign under consideration. This means that for a movable sign, the counting of the drekkana starts from the sign itself, for fixed sign, the counting starts from the 9th from the sign and for dual signs the counting starts from the 5th from the sign.
Thus for movable sign, the 1st drekkana, for fixed signs, the 2nd drekkana and for the dual signs, the 3rd drekkana will fall in the sign under consideration and becomes the vargottama drekkana. If Moon is in vargottama drekkana and in fourth house from Mercury, it constitute Sarada Yoga (a yoga for divine mother Saraswati, the goddess of knowledge). Such persons will be interested in literary persuits and seeker of knowlegde. They can produce literary works which stay in the world for long.
The decision making and others influence on the native's decision making process can be seen from the influence on the 10th house and the 10th lord's placement. Here we consider the nature of the signs falling in the 10th house. If the sign falling in the 10th house is a Movable sign, the person is too flexible in accepting other's opinion. If the sign under consideration is a fixed, the person is too inflexible in accepting other's opinion. However, if the sign in the 10th is a dual sign, the person is adaptable and consider the opinions or others in their own merit. The planets placed in the 10th house are the ones who shall try to influence in decision making of the native. However, based on the nature of the sign, the influence others make on native will make a difference on the native's decision making process. The nature of the planets and their natural significations and lordship will define the quality of the influence on the native's decision making.
If there are no planets in the 10th house, then the placement of the 10th lord shall show the flexiblity. To know this, based on the speed of the planets the planets are divided into three groups viz. Moon, Mercury, Venus belongs to the fastest group; Sun, Mars & Jupiter belonging to the moderate group while Rahu, Ketu, Saturn belongs to the slowest group. It is advisable that the fastest planet should be placed in the fixed sign so that the native has good flexibility to give other's due consideration. The moderate planets do well in the dual signs and the slowest planets are well placed in movable sign. If a fast moving planet is placed in a movable sign, the native gets swayed by other's influence too fast. Same way, if a slow moving planet is placed in a fixed sign, the native is extremely inflexible to accept other's opinion or appreciate their viewpoints. No one can change the opinion of such natives, once they have formed one.