The Wii is the hot item these days--so why are review scores for Wii games significantly lower than those of Xbox 360 and PlayStation titles? Matt Matthews investigates the numbers behind the phenomenon.

While doing some data trawling through GameRankings recently, I ran across a phenomenon on the Wii that I hadn't really seen quantified before.

The average of all Xbox 360 reviews cataloged on GameRankings turns out to be almost 70%. The same number for the PlayStation 3 is over 73% and for the Nintendo Wii ... a dismal 64%. A picture says it best:
 

Normally, I'd be inclined to dismiss discrepancies in review scores, but a 9-point gap between the PlayStation 3 and the Wii is hard to ignore. Even the Xbox 360 has a nearly 6-point advantage over the Wii. (The standard deviation for these data sets is around 12-14 points, for comparison. However, that alone doesn't tell the whole story. Rather, one should observe that a subset of data -- the roughly 150 Wii games in the whole data set -- has an aggregate review score 6 points below the mean for the entire data set. That is the anomaly.)

While I think that the above data is pretty significant all on its own, I can imagine people raising various objections. For example, the Xbox 360 has been out a year longer than the other two systems, so maybe it has more good games bringing its average up. And the PlayStation 3 has 33% fewer games than the Nintendo Wii, so perhaps a lack of shovelware is keeping the PS3 average higher. If we attempt to level the playing field and only look at the top 10% of all games on each system, the picture evens out a bit for the PlayStation 3 and Xbox 360, but the Wii is still significantly behind: