This link indicates the date of birth as 1 march 1630 according to present day calendar.www.tifr.res.in/~vahia/shivaji.pdf
if we assume this day and time around 19:00 or 20:00 hrs (after sunset) and this is my basic analysis
1. simha lagna is the natural lagna for kings/ generals.
1. ravi is placed in 7th house and is exhalted in navamsa. his father was an accomplished sardar in adilshah's army. it is placed along with guru, causing a rajyoga.
2. chandra is in kanya rashi and is vargottam. shivaji was very close to his mother jijabai but somehow the chart does not bring it out strongly.
3. rahu / ketu is 10-4 justifies his staying away from his father, constant struggle and wandering to accomplish his goals. rahu and ketu are exhalted. his career started early in rahu mahadsha but his first success can be seen around 30, corresponding to rahi in 10th.
4. shani is exhalted and also in mooltrikona in D9. Shivaji was known as a shrewd strategist more that as a valiant general. because of his limited military strength, he avioded open conflict as far as possible. guru helps in this being placed in shani's rashi aqaurius (aquarius is reg as good for guru especially for the intellect / wisdom part)
4. venus is in enemy rashi of mars. shani dristi on venus. ravi in 7th n shani's rashi and shani having drsiti on 5th. maharaj lived frugally and probably was not very attached to his wives.
pls give ur views, i am much keen to know what other aspects could have contributed to this great personality.