This article is for amateur radio operators but can be interesting for SWL. I translate an article in French.
https://arml.r-e-f.org/pdf/les_concours_radio.pdf
The Fisherman and Hunter Technique.
English-speaking countries say: "Running" & "Searching and Pouncing," which I've translated as fisherman and hunter.
There are two ways to conduct a contest:
• We scan the frequencies, listen, and answer the "callers" (we'll call ourselves hunters).
• We make repetitive calls, and whoever wants to can answer (we'll call ourselves fishermen).
Obviously, during a contest, you can alternate between these two techniques.
The Hunters:
Hunters scan the band looking for a contact. You have to scan kHz by kHz and pay close attention to the received signals.
When you come across someone making calls (a fisherman), wait your turn and try to understand their answering strategy. Do they answer the first callers or the last?
While you wait your turn, be sure to note down the call sign of the fisherman and their control group. You will need these to perform a coherence test when it's your turn.
If you are unable to make the QSO, no problem, memorize the frequency and try again later when operating conditions are better.
Fishermen
Fishermen have a simple technique. They choose a frequency,
ask if it's free (standard courtesy applies), and repeatedly call out "CQ Contest" for
long minutes (30, 40, or 60 minutes). Every incoming QSO is welcome. If you're a fisherman, it's up to you to be quick enough to keep the other calling stations waiting.
When you're a fisherman, don't forget to QRZ at the end of the contact to say
"next," and every two or three QSOs, give your call sign. This will allow the waiting stations to note it down.
Do not exceed a 3- to 5-second pause between calls. Otherwise,
you risk not being heard by a caller scanning the
band. Or worse, if the frequency is good, intruders might try
to take it, either by calling on the same frequency (which isn't
very polite) or by calling 1 or 2 kHz off your frequency, which isn't any more
polite. You have only one choice: choose another frequency, or stay on
this one, indicating that it is already in use and that you are in a contest. If
you are using Morse code, use PSE QSY. In principle, things
sort themselves out. If you have a "strong and clear" signal, you
can try your luck. Be aware that if you ultimately have to change
frequencies, the ends of the band are quieter (less
congested).
Whatever the situation, there is one thing you must never forget:
…remain polite. Try to find a compromise between contestants and non-contestants; ultimately, the bands belong to everyone. Also, keep in mind that
even as a fisherman, you sometimes have to move… this will help you
put things in perspective.
The “hunter” or “fisherman” dilemma
To be a fisherman, you need a certain amount of experience.
The choice between hunting and fishing can be made as follows:
• If you have a powerful station (power, antenna, etc.) with clear and perfectly intelligible audio, don't hesitate, go fishing for QSOs; it's a good strategy.
• If, on the other hand, you have a low or medium power station, or
you don't dare call because you don't know what the response will be, let yourself be fished. Even if your signal is weak, you can
be a multiplier. For the "fisherman," you're already a QSO anyway, maybe even the one that will win him the match, so be sure he'll do everything he can to copy you.
Keep in mind that in a contest, there are more hunters than fishermen.
That's partly why fishing pays off.
Use this fact and make your calls.

