IGN GamerMetrics analyst Nick Williams recently took a look back at the predictions GamerMetrics made for Xbox 360 titles based on analysis of four primary factors -- awareness, engagement, purchase intent and game quality -- ahead of each title's launch with the aim of predicting the success of upcoming games. The chart below highlights GamerMetrics' performance record for these past predictions, with six of ten titles analyzed falling within +/- 25% of the actual sales during the first two calendar months on the market. The two predictions to fall within +/- 10% of actual sales were two of the most successful Xbox 360 titles of the year: Madden NFL 08 and Halo 3.

But one title stands out, as Williams explained, "While the model was able to accurately predict the market size for Halo 3, it did not foresee the cannibalization effect that Master Chief would have on other September releases." According to Williams, the most glaring example of the "cannibalization effect" was Midway's Stranglehold. Based on the solid marks the John Woo action film-inspired title received across a variety of metrics, IGN predicted 450,000 unit sales in the U.S. by the end of October. However, Williams says that Stranglehold, along with other September 2007 Xbox 360 releases including Medal of Honor: Airborne, Skate, Project Gotham Racing 4 and Spider-Man: Friend or Foe, saw significantly less sales than analysts had predicted. Says Williams, "The underlying reason behind this trend is Halo's unmatched replayabilty, especially with regards to the online multiplayer features. During September and October, a significant portion of Xbox 360 owners played Halo 3 exclusively, with little attention given to other new releases."