PredictLeague is an application that uses a simple back-propagation to predict the victorious team of League of Legends games.

So what is League of Legends? League of Legends is a multiplayer online battle arena video game developed and publied by Riot Games. It was released in 2008 and has slowly grown in popularity over the years. As of January 2014, over 67 million people play League of Legends per month, 27 million per day, and over 7.5 million concurrently during peak hours.
League of Legends is a multiplayer online battle arena where players control a "champion" in order to be matched in a short PvP battle. As of February 27, 2014, there are 118 different Champions from which to choose. Players gain levels from killing the opposing team's Champions, controlled by other players, and minions that regularly spawn and attack the other team's turrets, minions, and champions.

In the classic game mode, the map is typically divided into "lanes", which are paths that spawned minions take, the "jungle", an area between lanes where neutral monsters spawn, and "bases", where players spawn and can purchase items. The primary map, Summoner's Rift, features three lanes, commonly referred to as top lane, where bruisers (partially damage, partially tanky) and tank type champions tend to go. Mid lane, where assassins and burst damage carries tend to go, and bot lane, where the ranged DPS (damage per second) carries and their supports tend to go. The jungle is sometimes considered a lane, where an assassin or tank champion tends to roam in order to collect buffs and assist in the other lanes freely.

The player earns a small amount of gold every second passively, but can earn more by getting the last hit on minions, destroying enemy towers (referred to as turrets) that guard the lanes, neutral monsters located in the jungle, and killing enemy champions. With this gold, they can buy a variety of items in order to strengthen their champion for the duration of the game. On the classic Summoners Rift, Twisted Treeline, and Howling Abyss maps, the game is ended by destroying the enemy team's last structure on the map, called the "Nexus", from which minions spawn.

Source: Wikipedia