I ran a couple of queries and found the following
Site | Count of Post Reopened| Count of Closed Posts | Percentage of Closed
| | | posts that are re-opend
-------------------------------------------------------------------------------
SO | 2528 | 69498 | 3.64%
P.SE | 281 | 3049 | 9.21%
It would seem that since a higher percentage of closed posts got reopened on P.SE than SO I think the opposite is true. You have a better change of getting a post reopened on a smaller site.
Perhaps we should consider making it easier to re-open posts on SO?