Question about collecting crucible stats

I notice that a few fan sites are collecting stats from every game played, even if the player does not log into the site and request their pgcr. I would like to do something like this to grab some crucible data, but I'm failing to find the proper end point to get something like a global "recent matches" or anything of the like. From what I can see, it appears that the activity id used for pgcr retrieval is simply a number that is incremented with each new match played. Is the "best" way to gather data in an ongoing way to use this "feature" of the id and just start collecting reports at some number and continue until you find the "last" report then wait awhile and start collecting there until you find the new "last" report, etc? Or are the sites that are getting every match using some other method to collect data? Thanks in advance for the help! :)