Advanced MLB DFS: Splits

If you have reached this level, you’ve likely been playing some form of fantasy baseball for a while now. We might think about fundamentals as applicable to beginners, but there are fundamentals even an expert level player can learn — or at least brush up on. For DFS, that means understanding how splits can help you build your lineups.

Splits

Definition

When talking about splits in MLB DFS, we are often looking at how pitchers and hitters perform against lefties and righties. As a basic rule, right handed hitters see the ball better against left handed pitchers and end up putting up better statistics against them and vice versa. There are other splits, such as home vs. away, by stadium, batter vs. pitcher, etc.

Strategy

Lefty vs. righty splits

These are the most useful splits you can research, as they are predictive and easy to spot when looking at matchups. You can’t blindly play a left-handed hitter versus a right-handed pitcher. The odds are good that that righty does better against lefties, but there is a chance he has reverse splits or the difference isn’t that substantial. Finding those batters that put up much better numbers in splits is always a good idea in DFS, as you are paying for that hitter’s overall numbers but getting the numbers in the particular split for that game.

ISO and wOBA are my two favorite statistics to look at for hitters, so narrowing those two down for lefties and righties can only make them better.

Home vs away

How a player plays in his home ballpark versus on the road can be helpful, but aren’t as predictive as lefty/righty splits. Much will depend on sample size when looking at statistics based on what ballpark a player is playing. If you have a young player, there’s a good chance he hasn’t hit often enough in multiple ballparks to give you a good stat. Each ballpark favors certain types of hitters and researching that is going to be more helpful than home/away splits most often.

Batter vs. pitcher

There is very little need to spend much time worrying about how a hitter fared against a pitcher in the past. There are likely times when it is worth looking at, but those would be for instances with at least 30 or more previous at bats. Even then, I tend to stay away from this split, as it is too enticing. Yes, it would seem logical to pick a batter or pitcher who has had success in the past in the same matchup, but research bares out that past performance in this split isn’t predictive on average. I prefer to rely on wOBA, ISO, WHIP, and xFIP when looking at lefty/righty splits before even considering batter vs. pitcher splits. Yes, if a player is in a great situation, but has gone 0-20 with 12 strikeouts against a particular pitcher, I will have second thoughts, but there is a good chance that won’t be the case.