By the special retrograde motion the planets moving in the sky attain their highest chesta-bala; retrograde benefics yield auspicious results while retrograde malefics yield intensely harmful ones. Endowed with utmost motion, the strong retrograde planets bestow unbroken results and accomplish the native's objectives.
janmani vakrā ye grahās te phalaṁ tīvraṁ prayacchate | śubhārtheṣu viśeṣeṇa jātakasya hitaṁ bahu || gocare tu punar vakrā dṛḍha-phal-lābha-dāyakāḥ | ubhayatra tu vakratvaṁ balaṁ vardhayate smṛtam || 3||
Those planets that are retrograde at birth bestow intense results, especially for auspicious matters, giving abundant benefit to the native; retrogression again in transit grants firm attainment of fruits. In both contexts, birth and transit, retrogression is said to increase a planet's strength.