There's almost too much in terms of statistics out there for fantasy players to pore over on a routine basis, and I've mentioned many times before that with all that data at our fingertips, it's pretty easy to make a case both for and against the same players, cherry picking whatever suits your argument at the time.
That's why I like to simplify things a bit and look to shortcuts and single stats that can give you a quick, unbiased snapshot of which players are performing well for fantasy purposes in relation to their peers. It's by no means perfect in predictive accuracy, but it certainly can help you narrow down the waiver wire decision-making process, especially at a time when many fantasy players are participating in leagues where they may not have very many transactions left under league maximums.
For starting pitchers, average game score (AGS) has always been a favorite "snapshot" of mine, especially in points leagues. Game score, created by Bill James, sums up each start in a single number, adding value for batters retired and strikeouts, while deducting points for hits, walks and runs allowed. While it's not a one-to-one correlation, taking a look at a pitcher's AGS for the season tends to line up pretty well with points league value.