If games are reviewed based on past games the review is biased, end of story.
Maybe it's only my philosophy, but a game is supposed to be reviewed based on a stand-alone opinion, not an opinion that relates to past games. You can factor in a little bit, but you shouldn't make a blatant attempt to degrade a game based on past games...
Chrono being mentioned, Chrono Cross is always degraded because it's not Chrono Trigger. If it were Chrono Trigger, it'd be hammered. Since it's not, it's still hammered. It's not a fair game review, and I'm sure most reviewers will not give Lost Odyssey a fair review.
How does Halo 3 get such an insane review over Halo 2, which got an insane review over Halo 1? I'd think Halo 2 would have gotten an 8, and Halo 3 maybe an 8.2 for improvements, and docked because it's almost the same game still.
Numbers: Checker Players > Halo Players
Checkers Age and replayability > Halo Age and replayability
Therefore, Checkers > Halo
So, Checkers is a better game than Halo.