So, as of May 19, I have 63 responses to the poll. (Percentages were rounded to whole numbers.)
17 (27%) I haven’t had to make any, so zero
15 (24%) zero failures
11 (17%) one failure
6 (10%) two failures
14 (22%) three or more failures
One of the big mistakes I made was allowing the real question to be cut off of the top of the poll. Consequently, some people originally thought I was asking about the total number of checks, rather than how many were failed. That skews the results high.
Another big mistake I made was only stopping at “3 or more” concentration failures. It would have been easy to add more options for more failures, but I didn’t. If I count “3 or more” as 3, then it skews the results low. Hopefully these two mistakes cancel each other out to some extent.
The reason why I started the poll is that I suspected that many of the character creation guides placed too much emphasis on concentration checks. With about 50% of people not failing a check in three game sessions, it seems that concentration isn’t that big of a problem. There were only 65 failures for 62 people taking the poll; that makes only about one failure per three game sessions.
Although I’m sure some of the people took feats (Warcaster and Resilient Constitution) to improve their odds against concentration checks. That could have caused them no not fail as many checks, and those people could, justifiably, say that concentration was not a big problem because they made choices to mitigate the threat it would normally be.
I found this interesting. I wish I would have crafted the poll better, but it seems like a good starting place.