In the Treta sin took away one of its legs; and virtue had then (only) three legs. In the Dvapara, sin and virtue are mixed half and half.
अधर्मपादविद्धस्तु त्रिभिरंशैः प्रतिष्ठितः। त्रेतायां द्वापरेऽर्धेन व्यामिश्रोधर्म उच्यते॥