Quote:
Originally Posted by Flash Walken
Hmm, I don't know what I'm looking at here, but the trend seems to be consistently going down.
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The eyeball test can fool you when looking for trends. One of the things you have to look out for is a stable series of data, followed by a sudden one-time change and then a new stable series. The random noise can fool you into not noticing the change and thinking there is a steady upward or downward trend.
The first few seasons on Russell's chart show him as an average defenceman on a bad Columbus team, in which he was better than most of his teammates. Then he spent most of two seasons as an average defenceman on a good St. Louis team, in which he was worse than most of his teammates. Finally you have three seasons with the Flames, when he was markedly worse than Giordano and Brodie. Since those two were playing nearly half the minutes, everybody else's relative numbers skew downwards.
A player's numbers relative to his teammates can't be treated as a series when he keeps changing teams.