Yes, he does. Although his scale is a bit off, it's better than most other reviewer. I don't know how much better a game that got 9.0 on GameSpot is compared to a game that got an 7,5.
But I do know that if a game got just a hint of positive from Yahtzee it's worth looking into, and if he enjoyed it, I probably will to. Also, his taste in games is pretty much the same as mine, except I like RTSs.
Nobody can say that his reviews are inaccurate, just a bit taken to a extreme.
It should also be said I'm a student, and I buying a game will result in me eating noodles for 3 weeks, so a game have to be awesome, or I would starve for no good reason.