The study of on-line game usage is typically limited due to the proprietary nature of the industry. To overcome this, we have collected several unique data sets that allow us to analyze properties that have not been possible previously. These data sets include the following:
Individual player data: In order to study the behavior of individual players playing a representative on-line game, we examined the activity of one of the busiest and longest running Counter-Strike servers in the country located at cs.mshmro.com [14,15]. Counter-Strike (a Half-Life modification) is currently the dominant on-line game with the largest service footprint of any game at 35,000 servers and over 4.5 billion player minutes per month [16]. Of all of the active Counter-Strike servers, cs.mshmro.com is among the busiest 20 servers as ranked by ServerSpy [17]. The server averages more than 40,000 connections per week, has hosted more than 400,000 unique players within the last year, and has logged more than 60 player years in activity since its launch in August 2001. Table 1 describes the trace collected from the server.
GameSpy aggregate player population data: One problem with measuring on-line game usage is the limited access to game server hosting data. Game companies typically keep the access and usage behavior of their players confidential. There are two factors that enable the measurement of aggregate game player populations, however: (1) on-line games use a centralized authentication server to keep track of the players that are playing and (2) information on overall player numbers per game is usually exported publicly. Several game portal services collect such player numbers over a large number of games and report the information in real-time. Among these services is the GameSpy network, which provides real-time player population data on individual games in a structured format that can readily collected and analyzed [18]. Currently, there are over 550 on-line games that are being tracked across various genres including first-person shooter games (FPS), massively multi-player on-line role-playing games (MMORPG), real-time strategy games (RTS), card and board games, and sports games. The most popular games tracked by the Gamespy network are from the FPS genre however, and therefore when we refer to gamers we are predominately referring to FPS gamers. To study on-line game population behavior, we have collected a data feed from GameSpy for more than two years since November 2002. Our redundant collection facility periodically samples the GameSpy data every 10 minutes. Note that the availability of the data is sensitive to many factors, including service outages at the portal and our own outages. These outages have been manually removed from the data analysis. Table 1 describes the data set which includes over 50 million measurements and represents more than 300,000 years of player time spent on games over the course of the last two years.
Content-distribution network: One of the common features of on-line games is their ability to dynamically update themselves. To support this feature, many games employ custom, game-specific, content distribution networks that deliver new game content and software patches to clients when needed. One such network is Steam [19], a multi-purpose, content-distribution network run by Valve which is used to distribute run-time security modules as well as client and server software patches for Half-Life and its mods such as Counter-Strike and Day of Defeat. The network consistently delivers several Gbps of content spread across over 100 servers. In order to analyze the resource usage of Steam, we have collected its data feed over the last 6 months, a duration that has seen Steam deliver more than 6 petabytes of data. Table 1 describes the trace collected.
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Data sets