When a planet is in the same sign in the natal chart as in the Navamsha (ninth divisional chart) it is said to be vargottama. Varga means division and uttama means best, so vargottama means "the best division." An important use of the Navamsha chart is to confirm the strength of the planet in the natal chart. A vargottama planet's indications are reinforced, and thereby strengthened, because of the repeated placement in the same sign, which is why it's the "best division."
A planet has a one out of nine chance (11.1 %) of being vargottama since the Navamsha chart is the ninth divisional chart. Since there are nine planets there is usually one planet that is vargottama in any natal chart.
In the Vedic astrology chart of movie actor Harrison Ford you'll find that both his Sun and Moon are vargottama in the sign of Gemini. This reinforces the communicative, witty and charismatic qualities of his Sun and Moon in Gemini that have contributed to his popularity and success.
Harrison Ford's Natal Chart
Harrison Ford's Navamsha Chart