In "Spam Suspicion Level for Topics" and the tutorial:

wpForo Spam Control

This is a core spam detecting function which works based on the level of spam suspicion. We recommend keep this option enabled and set the suspicion level from 20 to 60. This system checks all posts of spammers, then compare them, and then it tries to understand whether they are spam or not. If you enable “Ban user when spam is suspected” option, then you should periodically check the users’ status and make sure the banned user is a spammer, because there is no way to automatically detect spammers with 100% correct result.

it is not clear whether the value refers to:
1) the level of protection (the higher, the stricter).
2) the level that the messages must reach to be considered spam (the higher, the less strict)

that is to say, if I want to avoid more spam, should the value go up or down?

thanks