Confession: I'm a stat geek. I have no problem admitting it. While the advanced metrics have increased our understanding of the game, they still haven't completely made their way into Fantasy. Yes, there are places where you can customize your stats to include advanced formulas, but, for the most part, traditional stats prevail.
That's actually a good thing for the savvy Fantasy owner looking for an edge. While knowing a player's BABIP or FIP won't help you score points, it could be a key factor in making a trade. BABIP, batting average on balls in play, is often referenced on the Fantasy Baseball Today podcast, so I'll spare you the explanation there. But it's one of the most vital resources Fantasy owners have at their disposal.
Here are two other advanced metrics I'll use when making fantasy decisions:
wOBA - wOBA is an advanced stat that measures offensive production. An average wOBA is about .320 for reference. What I've done lately is looked at team wOBA when considering which pitchers I should start. It can be tough to get a handle on how a team's entire offense has performed, and wOBA helps with that. So, if my pitcher is facing the Red Sox and Royals next week, I can see how both team's are performing offensively. Right now, neither is playing that well, which might lead me to start that pitcher. At the same time, keep in mind that early samples can be misleading. The Red Sox won't be this bad offensively all year, so you'll be better served also looking at stats from last season in order to get a more accurate picture of offensive performance.
wRC+ - wRC+ is pretty similar to wOBA, but there are some key differences. wRC+ is measured on a different scale. For wRC+, 100 is league average. wRC+ also takes parks into account, which is important. So, using wRC+ in the same scenario above, you might notice that the Rockies aren't actually as good offensively as wOBA suggests. That's due to the team's strong home park. The opposite might happen with the Padres, who play in cavernous Petco. wRC+ is more helpful with teams that play in extreme ballparks.
I've been using both of these tools when setting my weekly starting pitchers the past few weeks. There are plenty of other advanced stats that can play a role in Fantasy leagues, but these two are a good start. If there's interest in seeing this type of thing in the future, I can always provide more blog posts. Let me know in the comments.