The Navamansha chart displays the luck of a person in general. Why so? If you remember the post on 9th house:
Then you will see that the 'good luck' as we see in our lives comes through good deeds or the good karma that we accumulate from our previous lives. So, if you have a strong D9 chart (or the 9th house), it actually that you have been a overall good person doing all sorts of goods deeds in the previous lives.
Well, what exactly you did can be determined through the 12th house of your chart or more precisely the D60 chart. For example if you have good placement of Venus in your D60 chart, it would actually mean that you behaved good with your wife and you were gentle and behaved well with women in general in your previous lives. Similarly, if you have a strong Mars in your D60 chart, it could mean that you did something good for masses (general public) in general or maybe you were a warrior in your previous life, who protected people.
Hence, your luck will be reflected from your D9 chart and if you see carefully your D1, D9 and D60 charts will be in agreement when it comes to the fruits you reap in your current life.