Home Field Advantage

One of the most unique things for baseball compared to other sports is that not all fields are created equal. Rather than provide anecdotes about the altitude in Denver, the Soto Porch in Tokyo, or the retractable roof in Los Muertos, I set out to determine exactly how different each park is.

MLB Baseline

See Figure 1 in reference document.

The first thing I did was extract data from the 2019 Major League Baseball ballparks. I calculated how frequently each park would have good weather, average weather, or bad weather, and then I used that to determine the average factors that the park truly has.

Using this baseline, an "O Rating" of 33.4 would be a neutral ballpark, not skewing offensively or defensively. As expected, Coors is at the top with an astounding 68.0 and the bottom is rounded out with Citi Field all the way down at 15.3.

Custom Ballparks in SBa

See Figure 2 in reference document.

My favorite thing about ballpark factors is how they influence team building strategies from a player acquisition point of view... If a visiting team doesn't say "fuck your ballpark" at least once in a series, you should probably consider changing your factors in the offseason
-Ryan, Vatican Angels

I used the same calculation on all SBa custom ballparks and the average O Rating was 34.9, slightly above that of the MLB. So it seems that our parks are pretty in line with the traditional set, but what about our extremes?

Honestly, not that crazy. Quezon City is known for their offense, but is still well below Coors Field. The humidor installed in Las Vegas has done its job and the Bandits are now a pitcher paradise not seen in the MLB since 2001 Pac Bell.

Team Records

See Figure 3 in reference document.

So we've got a really nice spread of offense and defense, but does that translate to team success? To find out, I looked at team records through the first 5 weeks and compared them to team home records. Only three teams (Tokyo, Dallas, and South Burlington) have identical home and away records. There are seven teams with better records and home and eight who are better on the road.

The Denver Zephyr have only played four home games on the season, but their 3-1 mark is the top home win percentage in the league despite currently being 9-9 overall. Meanwhile, the aforementioned Las Vegas Bandits are struggling to take advantage of their humidor as they are 6-6 on the road but only 1-5 at home.

As a league, we are 85-91 at home. With having park factors established pre-draft and some teams clearly building around their home field, being 6 games under .500 at home a month in was absolutely not what I expected to find!

Individual Performance

See Figures 4 and 5 in reference document.

Slightly harder to quantify, there are two results that are indicative of a player benefitting from or being crushed by their home ballpark. Using the O Ratings above, we would expect to see the "green tier" teams with a higher number of Ballpark Home Runs and Singles, however this does not mean that "red tier" teams would lead the flyout/lineout totals because their team composition may be built to not have ballpark checks at all. A quick glance at the BPHR leaderboard shows that this is in full effect, with West Virginia lapping the field having 4 of the top 6 leaders in ballpark-assisted-dongs.

A team level look shows that there are only three teams who have passed more ballpark checks than they have failed. West Virginia, Monterrey, and the road warrior Denver Zephyr. All three of these teams are in the top four offensive parks, and they've all played each other already, so this is not really a surprise. Build for offense, receive offense. The bandbox in Quezon City has not yet proven fruitful for Petra and Caleb, but look for this to change as the dice start rolling their way. That offense and park are too juicy to stay down much longer.

What about pitching performance?
See Figure 6 in reference document.

Unfortunately, we do not track ballpark home runs or singles allowed by pitchers, so this data will not be quite as accurate. There is one thing that is certain though, and that is that Quezon City is once again an outlier. Despite playing in Coors Lite, they have only allowed 18 total home runs on the season. The WonderWolves, even with playing 14/20 games at home, have given up the second most home runs to date. The rest of the league has very loose correlation that really doesn't mean much of anything. I looked at overall hits allowed as well (since we do not tie extra base hits to the pitcher), and there's just not a lot of correlation there either.

What does this mean?

See "HFA Conclusion" tab in reference document.

Don't worry, baby birds. I'll tell you.

Actually, I really won't. Because all this data leads me to believe that our custom parks are a fun thing to have but at the end of the day, nobody is truly winning or losing because of their ballpark. Would this have held true last season? I can't be sure and I'm not spending the next three hours like I spent the past three doing the research again. But I wasn't about to end on something non-controversial like that, so I extrapolated all of the data I used into one number to definitively determine which teams are most benefitting from custom ballparks (not necessarily their own custom ballpark, but maybe).

In conclusion, the overwhelming evidence proves that Cal sux.