|I know that there are many "data problems" in this site. The massive quantity of chess results throughout history makes it very time-consuming to get the data very clean. I feel that I have made great improvements on my previous efforts, especially in the 19th-century data, but I know there is still a lot of room for more improvement. Please let me know if you have more specific information about a particular event. Especially which month(s) of the year it occurred in, because that has a big impact on the ratings (which are calculated monthly). If you see somebody's rating gradually going up over the course of a year, rather than a big spike all at once, that's typically because I am missing the month from a key event and it's spread evenly over the course of the year instead. But if you see duplicate players, or wrong tournament results, or incorrect birth dates, or missing death dates, or spelling errors, all of those would also be great for me to know about so I can fix. I have had more than one person contact me about their own personal information on the Chessmetrics site, which is always fun to hear. I will certainly give credit to people who help me out. I can't promise that I will fix things right away but I do plan to rerun the rating calculations perdiodically and post them on the site here. I have made significant architectural changes on this version of the site to make that process more practical.