Daily fantasy baseball, like all daily fantasy sports, is a game of edges. You are trying to predict player performance better than your opponent(s). In baseball, this is somewhat tricky. The best hitters only reach base 3 out of 10 times. The best picks can go 0-for-4 and the worst picks can end up outscoring everyone.
Our goal should always be to make the right play. If we take a guy that has a 31% chance of getting a hit and our opponent takes a guy that has a 30% chance of getting a hit, we are going to come out ahead in the long run. So as daily fantasy players, we should be doing anything and everything to find those marginal percentage points we can add to our likelihood of succeeding.
Sabermetrics have become a big part of baseball. Books like MoneyBall and The Extra 2% talk about how real baseball teams use sabermetrics to do exactly what we are trying to do: gain an edge, however small, over their opponents.
Sometimes the batter-versus-pitcher (BvP) play of the day will go off or you will lose to a guy who played the "hot hitter" based on the belief the hot streak will continue. But over the course of the season, we can beat these opponents through our use of, quite frankly, better stats.
Offensive Stats to Know
wOBA stands for weighted on base average. It is similar to batting average and on-base percentage, but a much better indicator of a player's talent. Batting Average treats all hits as the same and fails to include walks (which obviously have value). On Base Percentage (OBP) includes the walks, but still treats everything as the same, which they are obviously not.
wOBA improves on these metrics by weighting individual events (1Bs, 2Bs, BBs, etc). The weights change every year, based on league averages. But the end result is a single statistic we can use to quickly determine a player's offensive ability.
By using this stat, you can not only get a better read on a player, you can also do it more efficiently than by looking at something like their triple slash line. When it comes to analyzing information, anything that allows to do it faster and better is a great tool.
ISO is isolated power. It is an indication of how often a player hits for extra bases. Now many people will look at slugging percentage for this, but ISO is a slight improvement because it represents the difference between a player's slugging percentage and their batting average. It is a simply a summary stat that save you the time of looking up both slugging percentage and batting average.
It is a nice supplement to wOBA because it focus more on the power/extra base side of things. So by looking at the two stats together, we can get a really good picture of what a given player does at the plate.
The one thing that wOBA and ISO lack is context. And that is where weighted runs created (wRC+) comes in.
This is similar to wOBA in the sense that it arrives at one number to quantify a player's offensive contributions. In this case that one number is how many runs the player was worth to his team. And the + part of it is where the context comes in. wRC+ controls for park effects and compares a player's performance to league average, with 100 symbolizing average performance.
That means that a wRC+ of 110 means a player was 10% better than league average. On the other hand, a wRC+ of 85 would mean a player was 15% worse than league average.
I like using wRC+ because of the context it gives. Saying someone has a .200 ISO might not mean much to you if you don't know the general range of ISOs. But saying someone is 25% better than the league average offensively is easier to understand and that info can be put into use.
If a player plays in a pitcher's park, his wOBA and ISO will likely be lower than a player of similar talent that plays in a hitter's park. But using wRC+, we can see that these players are about the same. And that is very applicable to daily fantasy, as it can be used when a player is on the road (away from his extreme home park).
Pitching Stats to Know
Fielding Independent Pitching. When it comes to pitching, there are things a pitcher can control and things he can't. ERA doesn't distinguish between the two, which means that it leaves a lot to be desired in terms of predicting future ERA.
Here is what pitchers can control: strikeouts, walks, home runs, hit by pitch.
Here is what pitchers can't control: pretty much everything once the ball is put into play.
By focusing on just the things a pitcher can control, we get a better idea of what they can actually do. And we are able to better predict what their future ERA might look like.
FIP strips out defense, luck (Batting average on balls in play) and sequencing and assumes that a pitcher would just get league average performance on all of the things they don't control. What's left is their FIP, which usually paints a more accurate picture of their performance than their ERA (which fluctuates based on things they have no control over).
Some players can consistently have their ERA beat or lag behind their FIP, but in general, we can expect an ERA to regress to the FIP.
This comes in handy in fantasy. If we see a guy having success but with an FIP much higher than his ERA, we know that he is unlikely to continue to be this good. On the other hand, if a guy is struggling but has a much lower FIP, we can bet on his lucky turning around and for him to get better results.
There is usually a bit more to the story, but this is a quick and easy way to see if a guy is likely "for real" based on early performances that attract attention (either positive or negative).
Expected FIP (xFIP) builds off the ideas of FIP, but controls for one more variable: the amount of HRs a pitcher allows. FIP treats this as something a pitcher can control. xFIP argues that this might not be true since a pitcher's HR/FB rate fluctuates from year to year.
So xFIP figures out how many HRs a pitcher "should" have allowed based on a league average HR/FB rate. So xFIP has many of the same uses as FIP, it is just a slighty improved version. But like FIP, there are players who can maintain an ERA that is different from their xFIP or FIP over long periods of time. But that is a more advanced statistical concept.
But just looking at a pitcher's xFIP in comparison to his ERA, you can improve your understanding of his skill and improve your ability to project him going forward.
These stats can all be found on Fangraphs.com, along with more in-depth explanations, the math behind them and the benchmarks for each one.
Immersing yourself in the countless tools and articles that Fangraphs has to offer is a great way to learn more about the game and sabermetrics. Even though the articles aren't written with daily fantasy (or even any kind of fantasy in some cases) in mind, doesn't mean that the information and ideas don't have fantasy applications.
Understanding these stats and knowing what they are telling us can give us a small advantage over the people that don't. And there are a lot of people playing daily fantasy baseball that either don't know/look at these stats or look at them but don't truly understand them. They are basically the Ruben Amaro Jr. of daily fantasy. Don't be like them.