We're in a new information era in hockey (at least new in a sense of public attention), with an increased emphasis on number crunching and statistics. There's a prevailing thought that, much like counting cards or playing the lottery, a finite equation can be used to predict future results. But some statistics and statistical concepts we use aren't as complicated as predicting what card will be drawn next from out of deck.
One thing to keep in mind when evaluating fantasy hockey goalies is regression.
Simply put, every player has an average stat line he produces. If a player is performing above or below that line, it's expected he eventually will produce more or less to achieve his average.
For example, during his career Washington Capitals captain Alex Ovechkin has scored on 12.3 percent of his shots. So if out of the first 100 shots Ovechkin takes in a season six (or six percent) go in, we would expect that number gradually to rise as he continues playing.
The same concept can be applied for goalies. The Boston Bruins' Tuukka Rask carried a career save percentage above .928 into this season, well above the League average. But Rask, for a number of reasons, has seen his save percentage drop to .912 through 21 games this season. The last time Rask had a save percentage below .920 for an entire season was 2010-11 when he was backing up Tim Thomas.