In many situations, fast play is effective, but there are also situations where slow play is more effective.
In this article, I will use some examples to summarize which play is more appropriate and how to think about it.
◆Slow play and fast play◆
●Wet board ⇒ Fast play is effective
Hand (BB) 
Flop: You call 
a raise from the BTN with the BB holding the hand.
The flop is a wet, draw-heavy board.
You hit a middle set, and the BTN corners you after you check.
What should you do in this situation?
On a draw-heavy board like this, even if your opponent has a strong made hand like an overpair or two pair, when the turn comes down with a diamond or a card that can make a one-card straight like a 9, 6, or 4, you’re stuck with no way to move.
This means you miss out on value, and if your opponent has a draw, you’ll end up showing the turn cheaply.
On boards like this, you should check-raise to protect your hand while still getting value.
You can then balance your value hands with semi-bluff hands, such as 
strong combo draws like or backdoor draws like .
●Dry board ⇒ Slow play is effective
Hand (BB)
Flop: You call 
a raise from the BTN with the BB . The flop is a super dry board with no draws. You hit a middle set, check, and the BTN card counters. What should you do in this situation?
On a dry board like this, the river situation is almost the same as on the flop.
This means there’s no need to protect your hand.
Furthermore, on a board like this, the original raiser’s chance of a CB will likely be high, and if you check-raise, you’ll deprive your opponent of the opportunity to bluff.
And if your opponent has a strong hand like a K or higher, there’s a good chance they’ll bet on the turn and river. On
a board like this, you should just call your opponent’s CB and wait for their hand to improve or for them to bluff.
●Tendencies of the other party
What kind of player is your opponent?
Does he not fold top pair, or any pair, or is he a player who likes to bluff?
You will need to change your play depending on that.
If your opponent is a calling station, it is more profitable to inflate the pot than to play slowly on a dry board, and you should increase the raise size and aim for maximum value.
If you are a player who likes to bluff, playing slowly even on a slightly wet board is profitable.
For example, consider the case where your opponent is an aggressive regular player who overbet against a capped range.
A raise from the BTN , the regular player in the BB called with a HU.
The flop was a HU 
and the BB checked.
On this flop, the BTN has an overcard, a gutshot, and a backdoor flush draw, giving them a strong enough hand to corner.
However, by incorporating a few of these hands into their flop checking range, they can adjust against aggressive opponents.
If a T falls on the turn, they’ll have the nut straight, and if a Q falls, they’ll have a strong top pair, which will be very profitable if they attack the BTN’s capped range after the turn.
In this way, it is important to take into account your opponent’s tendencies, think comprehensively, and play appropriately for each situation.
