Using Home Field Advantage in MLB
Using Home Field Advantage in MLB
In addition to a full time job as a software product manager, Alex Zelvin works part time for Fanduel.com (Zoobird on FanDuel) and co-owns Dailybaseballdata.com
Home field, home court, and and home ice advantage are all huge factors in the other major sports, despite the fact that the characteristics of each park or arena are very similar. Despite extensive research by many people on the subject, there is still no general consensus on why such a strong advantage goes to the home team in these sports. Oddly, home field advantage has a much less powerful impact in baseball, despite the fact that each field really is unique, with a variety of differences that could easily favor a player who is used to them.
That said, home field advantage is still a big enough factor that it’s worth considering when setting your lineups for each day’s contests. It’s particularly valuable if you understand how home field advantage impacts statistical performance, and therefore which players stand to benefit the most.
The area that is most strongly impacted makes some sense. A large part of home field advantage comes from the number of triples that teams hit (and allow). That seems to make sense. The difference between a triple and either a double or an out is often based on how quickly and cleanly the outfielder fields the ball. And that can be effected to a great degree by their familiarity with the specifics of the field…how fast does the ball bounce on the surface, where does the warning track start, how does the ball bounce off of an oddly angled part of the wall, and more. It would follow that for hitters, those who hit a lot of triples will benefit the most. It’s hard to imagine that Bengie Molina is going to gain more than a triple or two (if that) no matter how favorable his home park is. On the other hand, guys like Jose Reyes, Carl Crawford, and Curtis Granderson might gain the equivalent of as much as 4 or 5 triples per year if they’re playing in the right park.
The second major impact of home field advantage is more surprising. Strikeout and walk rates are superior for players at home. One theory is that umpires treat the home team more favorably. Another theory is that hitters may learn to ‘see’ the ball better against the backdrop of their home park. In any case, home hitters strikeout less frequently and walk more frequently. The lack of strikeouts leads to more hits, as their batting average on balls in play remains the same. And the excess hits and walks lead directly to more runs.
There are some other interesting statistical effects of players being at home or on the road. For example, there are games when the home team doesn’t need to bat in the ninth inning and where the visiting team doesn’t need to pitch in the ninth inning. That limits per game totals for players in those situations, without having any impact on per at bat statistics.
Another statistical oddity is that the way wins are credited causes starting pitchers to get a greater proportion of wins on the road than at home. The following example illustrates why. Assume that the starting pitcher throws six innings, and that the score is tied after the sixth inning. If the starting pitcher is at home, then a reliever replaces him in the top of the sixth inning. Assuming a scoreless half inning, then when the pitchers’ team scores in the bottom of the inning, the reliever will be credited with the win. Now look at the same situation on the road. The pitcher’s team scores in the top of the sixth inning, giving him the win, regardless of what the relief pitcher does in the bottom of the inning. Because they will typically perform better at home, this scoring oddity doesn’t mean that you should favor starting pitchers on the road…but it certainly means that middle relievers are much more valuable at home. It may create a different mix of wins vs. saves for closers, depending whether they’re at home or on the road.