For each episode of Fantasy Rounders, there is a considerable chunk of digital space that is devoted to platoon splits in order to shape the contextual value of hitters. These splits are the first item of study when constructing each day's lineup for DFS, due to the pervasiveness and the magnitude of the platoon effect throughout the league, and they often reveal opportunities to seize in the market given that platoon splits play at most a modest role in determining the daily salaries of available players; knowing a batter's platoon context allows a gamer to build in a value adjustment based on the opposing starter on the hill that day.
Over the years, I have found platoon splits to be a fairly reliable indicator of relative strengths and weaknesses, such that they take precedence when slicing and dicing the numbers during each night's research. Some major-league teams have put a dynamic premium on platoons, constructing vastly disparate lineups based on the handedness of the opposing pitcher – the Rays, Indians, and Athletics readily come to mind – and the underlying data supports everything from stacking a lineup with platoon bats to the parade of late-inning relief changes that have become such a major part of the modern game. Consider the following data:
LHB vs. LHP
RHB vs. RHP
RHB vs. LHP
LHB vs. RHP
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The performance of left-handed batters form the crux of the platoon advantage, with a 73-point swing in OPS when facing southpaws versus right-handed pitchers. Lefty hitters versus righty pitchers result in the highest offensive performance in all three slash categories as well as the best ratio of strikeouts to walks from the batter's point of view, followed by the lesser platoon-advantage scenario of right-handed bat versus left-handed arm. The true outlier in this slash matrix is the lefty-lefty matchup, particularly in the power categories, so it's no surprise that so many of the batters that are highlighted in this space hail from the left side.
The platoon effect is clearly nonlinear, impacting some batters more than others, and there are those hitters who buck trends to post reverse platoon splits (more often RHB's, such as Mike Trout and Adam Jones), but the same-side dent to hitter stats are widespread. There are also pitchers who are more or less vulnerable to platoon effects, and in the case of many arms there is a mechanical underpinning to the degree of a pitcher's split.
In general, pitchers with lower arm slots (who have more lateral variation in their pitch trajectories) tend to have larger platoon splits (the Justin Masterson model, +185 OPS against LHB), whereas their over-the-top counterparts are more likely to post minimal splits (the Yovani Gallardo paradigm, +27 OPS against LHB). The magnitude of arm slot on platoon splits is a topic for further research, but the framework of the argument is supported by managerial tendencies (particularly the use of sidewinders in the bullpen) and anecdotal evidence.
However, platoons aren't the only splits that will take my focus when constructing DFS lineups.
Home field advantage is an accepted attribute that is nonetheless an afterthought for many gamers when it comes to DFS lineup construction. I have fallen prey to this ignorance myself, choosing instead to focus on the fact that road teams are assured of 27 outs on offense whereas the home team might only get 24, foregoing their last turn at bat if the game has already been decided. It has never driven my roster decisions, but the tie-breaker between two players has been road team over home team due to the possibility of an extra term, but I have admittedly one so while ignoring the 39-point advantage in OPS that is enjoyed by home teams throughout the game. We all know about the Coors effect and that of some of the more extreme ballparks, yet the across-the-board advantage enjoyed by home teams is worth considering. At the very least, I figure it negates the possibility of an extra turn at the plate to neutralize my preference for home or road.
DFS managers have less control over this bases-occupied split, since it is not predetermined prior to gametime like pitcher-based platoons and home-road splits. However, the degree of the split should not be ignored, and it helps to explain the snowball effect on both sides – players on good offenses (that put more runners on base) receive a concurrent boost to their own slash ratings, whereas pitchers who allow many baserunners tend to pitch even worse when the bags are occupied. The K rates are lower, the walk rates are higher, and the offensive performance of players improves across the board when bases are occupied.
Part of the reason for this is likely a holier defense with respect to positioning (as teams go for the double play), and another aspect is that many pitchers are demonstrably worse when throwing from the stretch as compared to the windup, losing stuff and mechanical repetition to take advantage of opposing hitters. So the takeaway from the standpoint of roster construction is to lean toward position players on stronger offenses and toward pitchers who keep the WHIP in check, but the relative lack of control over these dynamics make this particular split low on my list.
It's an exciting day for pitchers, with multiple hurlers returning from elbow woes to retake the mound for the first this season. The much-anticipated 2015 debut of Jose Fernandez highlights the slate, as the young right-hander will change the landscape of the pitcher pool at least once per week for the rest of the season. Fern is squaring off against another pitcher who hasn't pitched in about a year as he recovers from elbow problems, with Matt Cain of the Giants toeing the rubber in a game that could have both starting pitchers out before the sixth inning as teams ease them back into action. Another TJS survivor, Matt Moore, gets saddled with a difficult assignment, drawing Cy Young incumbent Corey Kluber and the Cleveland Indians. I won't be rostering these pitchers in DFS due to the unknown factor that comes attached to injuries in addition to the likelihood of a short outing, but I will be eagerly tuning in to each game. All three of these 2015 debuts will start early (12:10 pm EST start for each), so it's a good day to call in sick to work or to fake a cold to get out of school.