Convicted murderer Claude Bloodgood was rated 2759 USCF in 1997 and would have qualified for the US Championships by rating had they allowed him to enter. He achieved this by being the strongest player in the closed pool of the US prison system.
Approximately how good of a chess people play in prison ?

Strangemover wrote:
Convicted murderer Claude Bloodgood was rated 2759 USCF in 1997 and would have qualified for the US Championships by rating had they allowed him to enter. He achieved this by being the strongest player in the closed pool of the US prison system.
Bloodgood organized chess games within Powhatan Correctional Center in Powhatan, Virginia, which were by necessity with fellow inmates.[2] Many of these inmates were taught the game by Bloodgood, and thus began as unrated and inexperienced players. Bloodgood obtained USCF memberships for them. Some accused Bloodgood, with his intimate knowledge of the rating system, of rigging their ratings. The accusation was that he arranged for new prisoners to play rated games against other prisoners, who would deliberately lose, thus giving the new inmate an inflated USCF rating. Bloodgood, it is further alleged, then played rated games against the new highly rated prisoner, and each time he won, gained a few more rating points. This continued for several years, and by 1997 his rating rose to 2759, making the 59-year-old Bloodgood the second highest rated player in the nation. In comparison, at his retirement Bobby Fischer's rating was 2760, and several leading grandmasters were in the 2600s.

Yes he was an arbiter/tournament organiser rated around 2000 I believe before he killed his mother. So he could have rigged his rating but in any case the 2759 was clearly artificial be it through rigging or simply being clearly the best player in prison. He played the Grob often and wrote a book on it. Batgirl was mentioned and I believe she wrote an article/forum about him some time ago.
They do have lots of free time and quite a choice of chess related literature.
So I was just wondering what is the average level of play there and what would be maximum strength?