Keeping an eye on the cards your opponents pick up and discard is an essential part of studying them. You can get a better idea of the cards that are avaisatta/kinglable and likely to be in your opponents' hands by keeping track of the cards that are drawn and discarded. This can assist you in choosing which cards to keep & which to discard with greater knowledge. Keeping an eye on your opponents' behavior and body language is another crucial component of observation.