Explanations

Active users = users that entered some nick and placed at least one dot (with AI or against human). As usual, some users may be counted twice (or more times). For example, this may (or may not) happen after changing the username.

Dots = total number of dots placed by all users during a day (with AI or against human). This is intended to measure users' activity.

All games = number of saved sgf files with all games (free and rated) from that day in which there were at least 24 moves, or 16 moves for tournament games. (Normally only games with 24 moves or more are saved, but tournament games are exceptional -- they are always saved regardless of the number of dots. Tournament games having less than 16 moves made are not counted.)
Also note that sometimes because of the restarts games from the previous (at most) 24 hours were lost. This happened for example on March 4, 2011 or May 13, 2011. That time sgfs had to be manually saved before the restart and we sometimes forgot about it.

Rated games = number of rated games

Notes:

• When the server was restarted for example at 8:00 am, then the stats from 0:00-8:00 were lost. For example: on 16.8.2011 the server was restarted at about 10:00 am, but despite the very low stats on 14.8.2011, it was not restarted then.
• High peaks are usually correlated with some math exams in Polish secondary schools. Examples: 2.11.2010 or 22.11.2011. This is because zagram.org is linked on matematyka.pisz.pl, a very popular web page about math for secondary schools.
• On 22.7.2012 at about 1:45 the server went down for maintanence. Due to technical problems, it was restarted only on 23.7.2012 at 14:11, after a break of about 36.5 hours. The statistics for 22.7 are just a lower estimate based on 2 saved games from that day (but the real numbers were probably not much higher, because on that day the server worked only from 0:00 till 1:45).
• On 25.8.2012 the server was restarted at 6:51, and then again (because of the bug) at 21:44. Stats are lower estimates based on the partial stats from 6:51--21:44 and from 21:44--end of the day.
• Stats from 21.11.2012 are lower estimates for the number of players (302 active players before the restart and 265 after, but we do not know how many of them were the same players), and quite accurate lower estimates of the number of dots, despite the restart.
• On September 4 and 9, 2012, the stats were lost.
• Until September 21, 2012, the stats denoted as on day n where gathered from 23:58 on day n-1 to 23:58 on day n. On September 22, 2012, the stats where gathered from 23:58 on Sep 21 to 4:00 on Sep 23 (so longer than usually). Starting from September 23, 2012, the stats denoted as on day n are gathered from 4:00 on day n to 4:00 on day n+1. We expect that this change will make the number of active players smaller - because players that play only around midnight contributed to stats of 2 days (before and after midnight), and now they will contribute only to the day before midnight, unless they play also after 4:00 am (or simply they also play on the next day).
• On February 3, 2013 (about 2:30--3:00 am), the server (and IP) of zagram.org has been changed. Although the kropki server was down only for less than an hour, it was unaccesible for many people even in the evening due to slow updates in DNS.
• On February 17-19, 2013, on matematyka.pisz.pl, the direct links to zagram.org has been changed to a page with a short description of the game and a simple problem to solve. The link to zagram.org is shown only after solving the problem. We expect that the number of users/day will decrease slightly, but hope to filter out those who are not interested in the game anyway.
• On July 25, 2013, zagram.org was moved to another server (from France to Germany). It was down for about 12 hours, and for some people even longer because of slow DNS updates.
• On September 29, 2014, zagram.org was moved to another server (still in Germany). It was down only for about 2 hours, for some people longer because of slow DNS updates. The stats were however lost and therefore the number of active users and played dots appear to be very low.
• From February 29, 2016 to March 15 there were often lags in the evening, making zagram hardly usable in the time 17--21. This was probably caused by a suboptimally configured http server. On March 16, 2016 (about 23:00 Polish time) the server was moved to a VPS. Playing was possible also by using IP as the web address, so the delay was minimal.
• Statistics for March 17, 2016 are for about 34h (from 2016-03-16, 23:05 to 2016-03-18, 9:05). Statistics for March 18, 2016 started at 9:07, the server was not restarted on that day, only statistics cleared.
• Statistics for June 24, 2016 are for about 40h (from 2016-06-23, 12:10 to 2016-06-25, 4:00), while statistics for June 23, 2016 are for 4:00--12:00 only. Zagram moved from one physical server (in France) to another one (in Germany) at about 12:00, 2016-06-23.
• Zagram was moved from one server to another on 2021-01-17, but due to certificate problem, started working completely on 2021-01-18. Zagram server was running without any restart from 2018-03-26 to 2021-01-17 (despite that some false restarts are shown below).
• Zagram was moved from one server to another on 2025-08-25 to 2025-08-26. At the moment of shutting it down, it was up since 2023-12-20, so for over 2.5 years without a restart.
• All times are given in Polish local time (which is UTC+1 from end of October to end of March of the next year, and UTC+2 from end of March until end of October).

Months averages