lead.created, it receives each new lead, whatever its score.
To send only some leads — a score of 4 or more, a job role that matches, people who commented at least twice — create a workflow on the Leads page. A workflow is the one place where you choose leads:
The filters are checked on the lead as it is when it is scored, and each time it comes back. When a lead matches for the first time, the workflow can add it to a list, notify you, and send it to one of your destinations as a
lead.matched event.
See Workflows for how they run.