First of all, you do it to get the most money you can from your hand. That is the most basic reason. You have a good hand, and you want to make sure the other players pony up more money.

You also do it to eliminate the other players. If you raise high, whether you are bluffing or not, players may well be intimidated and fold.

You also do it to get a free card, even though you actually have to pay for it. Still, raising can show another card in the flop.

You can also get information from raising — from the other players, of course. Especially if they have tells.

And, of course, if you are bluffing or just semi bluffing, you almost have to raise.

You may not be able to see your opponents’ faces, but you can judge their actions. For instance, pay attention to how quickly — or slowly — the other players bet. How long does it take them? A fast bet is generally indicative of a strong hand, while a player who is slower to bet is likely judging how well they can bluff a not so great hand.