In a recent answer on Meta Stack Overflow, Shog9 made the following note:
Accuracy is all over the map too. Some of our most prolific close voters routinely toss votes at questions that don't get closed in a timely manner - or at all.
I realized something—I don't actually have any idea what percentage of the questions I vote to close actually get closed. My ability to cast close votes is relatively worthless if I just splatter close votes everywhere like buckshot.
We don't want people throwing close votes willy-nilly—we want them to be snipers, shooting down the terrible questions like a well-oiled machine. Unfortunately, currently, it's extremely hard for a user to determine if their perception of what should be closed matches up with the rest of the userbase's.
Clearly, this data is available. It's just not accessible to the average user. I don't think this data should be public to anyone who wants to look at it, but I do think it would be extremely helpful for someone to view their own close vote history.
Ideally, I'd like to have something like this available to me:
Sure, this wouldn't help people who weren't interested in taking the time to look at the stats. But I think some people would be, and it would make them much more effective at closing wisely.