Over the last couple of weeks we’ve been seeing and hearing some discussions about the new Oracle Park’s dimensions likely leading to an offensive bust out in San Francisco. This talk, plus the Marlins moving their fences in, Toronto playing their home games at Sahlen Field in Buffalo, the Rangers playing in their new stadium and the Red Sox, Mets and Mariners all using a humidor for the first time we thought we’d check in and see how these parks are playing thus far.
In a typical season there are between 125,000 and 128,000 batted ball events. In 2020 there have only been 31,583 (Through 9/9), so this is a relatively small sample size. Also, the ball flies differently in hot and cold weather, low and high humidity and whether the game is being played indoors or out. The following data is not meant to be considered the final word on how these stadiums will play going forward but merely a look at how they have played from July 23, 2020 to September 9, 2020.
How the Data is Generated
Using the data provided by baseballsavant.com we find the results of all Batted Ball Events (BBE) in 2020 by Exit Velocity (EV), Launch Angle (LA), handedness (RHB and LHB), hit location (LF, LCF, CF, RCF, RF) and whether the ball was pulled, hit to the opposite field, pulled to an alley, hit to the opposite alley or centered. Taking all of these factors into account we come up with the average for how each batted ball event played out in all 30 MLB stadiums this season. Once we assemble all of the outcomes for the season we can then generate the expected stats for each batted ball event and compare them to the actual outcomes to get our park factors. If a park was expected to give up 50 home runs but it actually yielded 58 then the park factor for home runs is a 116. Conversely, if a park was expected to give up 50 home runs but only 42 were hit then the park factor for home runs is 84. 100 is league average
The Humidor Parks
Back on August 11 we wrote a quick article about the impact of the humidor in Arizona and the potential impact of a humidor at Fenway, Citi and T-Mobile in Seattle which can be found here. As was referenced in that article, on November 6, 2014 Ryan P. Morrison of SB Nation wrote a piece on the impact of the humidor at Coors Field and also included a chart that showed the potential impact of humidors in other parks around the country. Below is the chart for potential impacts in Boston, New York and Seattle.
| City | Humidity (%) | HR distance (feet) |
| Boston | 59 | +7.9 |
| New York | 53 | +2.2 |
| Seattle | 53 | +2.9 |
Note: According to current result/Weather.com the average yearly relative humidity is 67% in Boston, 63% in NYC (La Guardia), and 73% in Seattle. This may have been different in 2014.
Fenway Park
|
From July 23 to September 9, 2019 |
From July 23 to September 9, 2020
|
| Stat | Rank | Factor | Rank | Factor | +/-% | |
| Average | 16 | 99.4 | 1 | 108.1 | + 8.8% | |
| Home Runs | 24 | 93.5 | 4 | 108.0 | +15.5% | |
| RBIcon | 20 | 97.8 | 2 | 108.0 | +10.4% |
There’s a small sample size caveat here (1,343 batted balls compared to a normal full season of about 4,200), but it appears that Fenway Park has been given a pretty significant boost to its offense via the humidor. In 2020 Fenway Park has moved up 15 spots in batting average to 1, 20 spots in home runs to 4 and 18 spots in expected RBI on contact to 2. It should be noted that Boston’s highest relative humidity months are the ones that the season has been played in so far (July, August and September). However, May and June are two of the higher humidity months for Boston as well so this is likely a near full season trend. Should the organization choose to keep using the humidor this could be great news for your Red Sox hitters.
Citi Field
| From July 23 to September 9, 2019 |
From July 23 to September 9, 2020
|
| Stat | Rank | Factor | Rank | Factor | +/-% | |
| Average | 10 | 100.9 | 9 | 101.6 | + 0.7% | |
| Home Runs | 11 | 102.1 | 13 | 102.2 | + 0.1% | |
| RBIcon | 9 | 101.6 | 10 | 102.3 | + 0.7% |
Unlike Fenway Park, Citi Field has stayed steady. Of the three cities NYC (La Guardia) has the lowest relative humidity and stood to gain the least by using the humidor. As expected, the humidor appears to have had very little impact thus far. We’ll keep monitoring the situation next year to see if a full season’s usage nets different results.
T-Mobile Park
| From July 23 to September 9, 2019 |
From July 23 to September 9, 2020
|
| Stat | Rank | Factor | Rank | Factor | +/-% | |
| Average | 24 | 98.1 | 20 | 98.7 | + 0.6% | |
| Home Runs | 29 | 88.5 | 18 | 99.3 | +12.2% | |
| RBIcon | 24 | 94.1 | 19 | 99.1 | + 5.3% |
T-Mobile has also experienced a boost in offense. Not to the same degree as Fenway, but a definite boost. T-Mobile had gained 4 spots in batting average to 20, 11 spots in home runs to 18 and 5 spots to 19 in expected RBI on contact. Although Seattle has not experienced as much of a boost as Boston has it is worth noting that the summer months are the most humid months in Boston (Getting the biggest offensive boost from the humidor) where July and August are the two least humid months in Seattle. T-Mobile Park may have a lot more offense to give us next season when they are playing in the more humid months of Spring and Fall. Keep your eye on T-Mobile in September. The relative humidity rate climbs towards Seattle’s highest levels this month and in just six games played at the Mariners’ home park (two of them 7 inning games) there have been eighteen home runs hit. That’s 3.24 home runs per 9 innings compared to the 2020 MLB average of 1.35.
Ballparks With New Dimensions
Over the off-season both Oracle Park in San Francisco and Marlins Park in Miami decided to move in their fences to boost their offensive production. Oracle Park moved left-center field in from 404 feet in to 399 feet, straight away center field from 399 to 391 and right-center field from 421 to 415. They have also closed off an archway in right field that the organization believes will help to keep the prevailing wind that comes in from McCovey Cove from knocking down potential home runs. The Marlins moved the center field fences in from 407 to 400 and right-center field from 392 to 387.
Marlins Park
We’re already dealing with small sample sizes and, because Covid has had the Marlins playing an abnormal number of home games on the road, the sample size is even smaller here. The typical park has had between 1,000 and 1,300 batted ball events where Marlins Park has only had 553 through September 9th.
| From July 23 to September 9, 2019 |
From July 23 to September 9, 2020
|
| Stat | Rank | Factor | Rank | Factor | +/-% | |
| Average | 14 | 100.3 | 4 | 104.2 | + 3.9% | |
| Home Runs | 12 | 101.7 | 19 | 99.0 | – 2.7% | |
| RBIcon | 13 | 100.8 | 8 | 102.6 | + 1.8% |
The fences have been moved from 407 to 400 in center and 392 to 387 in right-center
| From July 23 to September 9, 2019 |
From July 23 to September 9, 2020
|
| Field | Stat | Rank | Factor | Rank | Factor | +/-% | |
| Center | Home Runs | 7 | 109.5 | 3 | 129.3 | +18.9% | |
| Right-center | Home Runs | 24 | 80.8 | 2 | 88.9 | +10.0% |
There’s little doubt that if the fences are moved in that home runs will increase, and they have, but with such a small sample it’s difficult to gauge just how much of the gains will stick.
*Weird stat of the season so far: Not a single one of the 133 batted balls to right field have gone for a home run at Marlins Park this season. Even stranger: Not a single expected home run has been hit either. Through this same time period last year 133 batted balls would have netted both an actual and expected 7 home runs to right field. Bizarre.
Oracle Park
Are we ready to get a little controversial now? During the same time span in 2019 Oracle Park allowed 38 home runs (4.27% HR rate). In 2020, Oracle Park has allowed 61 home runs (5.19% HR Rate). Obviously, Oracle Park is becoming an offensive park that’s vastly improved, yes? Ummm, not quite. As we mentioned with Marlins Park, if you move the fences in you’re almost undoubtedly going to have more home runs hit. It has improved, just not quite as much as the raw numbers of 38 HR’s versus 61 HR’s would lead you to believe. Let me explain. Our park factors are based on the number of actual home runs hit versus the number of expected home runs hit. If Park A gives up 1,000 home runs but there was expected to be 900 home runs then Park A is going to have the same home run factor of 111.1 as Park B that gives up 100 home runs with only 90 home runs expected. The only thing that matters in our park factors is what happened versus what was expected to happen. To use another example, the Twins broke the MLB team record for HR’s in 2019 but Target Field’s HR factor ranked 26. The Twins hit a bunch of home runs but they were expected to hit even more. Basically, teams are just plain hitting the ball better at Oracle Park this season, most notably, the Giants themselves. In 2019 Oracle gave up 38 home runs but only 44 home runs were expected. In 2020, Oracle has given up 61 home runs but 73 home runs have been expected!
| From July 23 to September 9, 2019 |
From July 23 to September 9, 2020
|
| Stat | Rank | Factor | Rank | Factor | +/-% | |
| Average | 28 | 95.8 | 12 | 100.5 | + 4.9% | |
| Home Runs | 30 | 86.8 | 29 | 83.6 | – 3.5% | |
| RBIcon | 30 | 90.7 | 28 | 93.7 | + 3.3% |
The fences have been moved from 404 to 399 in left-center, 399 to 391 in center, 421 to 415 in right-center, and the team has closed off an archway in right field that was previously open to the prevailing winds that blew in from McCovey Cove.
| From July 23 to September 9, 2019 |
From July 23 to September 9, 2020
|
| Field | Stat | Rank | Factor | Rank | Factor | +/-% | |
| Left-center | Home Runs | 11 | 104.8 | 25 | 93.5 | -10.8% | |
| Center | Home Runs | 20 | 94.0 | 21 | 89.1 | – 5.2% | |
| Right-center | Home Runs | 30 | 47.7 | 30 | 65.5 | +37.3% | |
| Right | Home Runs | 25 | 91.5 | 29 | 73.4 | -19.8% | |
So far, Oracle’s overall home run factor is actually down from 86.8 to 83.6. However, I don’t expect this to stick. As we’ve mentioned before, when you move the fences in there are generally going to be more home runs hit. One of the factors that the organization thought would improve the long ball to right field was the closing of the arch. The following are comments from Giants broadcaster Mike Krukow from Jake Montero’s article for KNBR.com on July 22:
“If you know the architectural history of this ballpark and you know it’s stunted on the right side because of the proximity to McCovey Cove, and they did two years of wind study and they designed that ballpark so it’s in the prevailing wind. It’s almost like you’re drafting behind a truck on the interstate on a bicycle. You get a free pass with the wind, but the wind wraps around you and that’s what the wind has always done at that ballpark. It wraps around the ballpark only with the unique design of the out of town scoreboard, with mesh fencing, and there’s a gate that’s open that allows the air to pass back from the right side of the field through the archway there, and back onto the field. When you stand there and shag during batting practice, you feel the wind at your back. It’s no secret as to why, since the doors opened in that ballpark, it’s so difficult to hit balls out to right field, especially for right-handed hitters. Balls get up there, the air hits it, and the ball drops like a turd from a giraffe. Straight down, done, see ya later.”
This year the home run factor to right field has actually gone down from 91.5 to 73.4. Full disclosure, I am not a physicist or a climatologist. However, the idea that closing the archway would be a positive influence on home runs didn’t make sense to me. The archway is below the fence line and, obviously, home runs are above the fence line. The very same prevailing wind that was blowing in from McCovey Cove is still there it’s just that anyone standing in right field can no longer feel it. I would imagine, if anything, that there would more of a force coming in to right field. The wind that would normally have passed through the archway and below the fence line is now being blocked and pushed up and over the fence where it can exert even more resistance to potential home runs. Again, I’m not a physicist or climatologist and I could be completely wrong, but the numbers thus far are somewhat supporting this position.
The New Parks
Sahlen Field
Sahlen Field’s center field sits facing South-Southeast with an 8 to 10 MPH breeze prevailing out from the right field foul pole to the left field foul pole all year long. Both the left field and right fields angle back from a 325 foot foul pole before squaring off at the power alleys (371 ft. LCF and 367 ft. RCF). The alleys then angle back inward forming a pointed A-Frame center field at 404 ft. Sahlen Field most resembles Nationals Park’s shape but it’s 12 feet shorter to left, 6 feet shorter to left-center, 2 feet deeper to center, 3 feet shorter to right-center and 10 feet shorter to right.
From July 23 to September 9, 2019
| Handed | Stat |
Rank |
Factor |
| All | Average |
10 |
101.5 |
| All | Home Runs |
5 |
106.7 |
| All | RBIcon |
6 |
103.3 |
| Handed | Stat |
Rank |
Factor |
| Right | Average |
19 |
98.4 |
| Right | Home Runs |
14 |
101.5 |
| Right | RBIcon |
8 |
98.8 |
| Handed | Stat |
Rank |
Factor |
| Left | Average |
3 |
102.7 |
| Left | Home Runs |
1 |
119.9 |
| Left t | RBIcon |
1 |
112.7 |
| Field | Stat |
Rank |
Factor |
| Left | Average |
8 |
103.3 |
| Left-center | Average |
8 |
103.0 |
| Center | Average |
12 |
99.2 |
| Right-center | Average |
25 |
96.0 |
| Right | Average |
10 |
102.9 |
| Field | Stat |
Rank |
Factor |
| Left | Home Runs |
6 |
112.0 |
| Left-center | Home Runs |
10 |
104.0 |
| Center | Home Runs |
10 |
110.0 |
| Right-center | Home Runs |
17 |
100.0 |
| Right | Home Runs |
13 |
102.1 |
| Field | Stat |
Rank |
Factor |
| Left | RBIcon |
4 |
107.7 |
| Left-center | RBIcon |
7 |
104.3 |
| Center | RBIcon |
13 |
101.1 |
| Right-center | RBIcon |
16 |
98.4 |
| Right | RBIcon |
15 |
101.2 |
Sahlen Field has definitely played as a very interesting park thus far. Despite the fact that left and left-center are the most offensively friendly fields it’s the left handed batters that have thrived the most. This does make some sense. The prevailing winds are out to left and opposite field balls are typically hit on a higher trajectory than pulled balls. This higher trajectory and steady winds gives the ball a chance to fly further than normal. Couple that with the friendly confines of 325 feet to left and 371 feet to the left-center alley and you have a recipe that serves up the number one ranked home run and RBIcon factors for left handed batters in all of baseball.
Globe Life Field
Globe Life Field’s center field sits facing Northeast with the prevailing winds blowing at 9-12 MPH from the right field foul pole to the left field foul pole. Previously, Globe Life Park faced Southeast with the winds blowing straight in from center field. Despite having the wind blowing in from center field on most days the old Globe Life played more to its dimensions than to its wind factors. While it had between a 112 to 113 home run factor to its smaller dimension center, right-center and right fields it only played as an 88 and an 86 to its tougher dimension high walled left field and 390 foot left-center field, respectively. With the new Globe Life Field having a retractable roof, and the summer months promising an indoor setting, it’s difficult to say how often or how much wind will play a role at this new stadium.
The left field line is listed at only 329 feet but it angles back quickly to over 360 feet before squaring off to 372 feet in left-center; 18 feet closer than the old Globe Life. Center field is squared off like the Rangers’ previous park but is 7 feet deeper at 407 feet. Right-center and right field are nearly identical in shape and distance as Globe Life Park at 374 feet and 325 feet, respectively.
| From July 23 to September 9, 2019 |
From July 23 to September 9, 2020
|
| Handed | Stat | Rank | Factor | Rank | Factor | +/-% | |
| All | Average | 8 | 101.9 | 26 | 97.0 | – 4.8% | |
| All | Home Runs | 28 | 89.4 | 30 | 81.6 | – 8.7% | |
| All | RBIcon | 21 | 97.7 | 29 | 89.8 | – 8.1% |
| Handed | Stat | Rank | Factor | Rank | Factor | +/-% | |
| Right | Average | 13 | 101.9 | 27 | 95.6 | – 5.7% | |
| Right | Home Runs | 29 | 89.4 | 30 | 76.5 | – 9.0% | |
| Right | RBIcon | 22 | 97.7 | 30 | 88.0 | – 9.7% |
| Handed | Stat | Rank | Factor | Rank | Factor | +/-% | |
| Left | Average | 6 | 101.9 | 18 | 98.6 | – 3.8% | |
| Left | Home Runs | 26 | 89.4 | 26 | 87.0 | – 7.2% | |
| Left | RBIcon | 29 | 97.7 | 27 | 91.9 | – 6.2% |
| From July 23 to September 9, 2019 |
From July 23 to September 9, 2020
|
| Field | Stat | Rank | Factor | Rank | Factor | +/-% | |
| Left | Average | 11 | 102.0 | 24 | 97.3 | – 4.6% | |
| Left-center | Average | 25 | 97.2 | 13 | 101.0 | + 3.9% | |
| Center | Average | 9 | 102.7 | 13 | 97.9 | – 4.7% | |
| Right-center | Average | 26 | 91.8 | 30 | 84.7 | – 7.7% | |
| Right | Average | 6 | 105.3 | 30 | 96.2 | – 8.6% |
| Field | Stat | Rank | Factor | Rank | Factor | +/-% | |
| Left | Home Runs | 30 | 68 | 30 | 66.4 | – 2.4% | |
| Left-center | Home Runs | 30 | 60 | 24 | 100.0 | +66.7% | |
| Center | Home Runs | 13 | 99.9 | 27 | 72.0 | -27.9% | |
| Right-center | Home Runs | 27 | 71.6 | 27 | 82.8 | +15.6% | |
| Right | Home Runs | 3 | 112.3 | 27 | 85.0 | -24.3% |
| Field | Stat | Rank | Factor | Rank | Factor | +/-% | |
| Left | RBIcon | 20 | 95.3 | 29 | 87.9 | – 7.8% | |
| Left-center | RBIcon | 29 | 79.1 | 15 | 101.2 | +27.9% | |
| Center | RBIcon | 8 | 103.1 | 27 | 88.0 | -14.7% | |
| Right-center | RBIcon | 28 | 82.0 | 30 | 82.9 | + 1.1% | |
| Right | RBIcon | 5 | 107.2 | 28 | 89.1 | -16.9% |
Year over year the new Globe Life Field has seen an 8.1% dip in offensive production with right handed batters seeing the brunt of that production drop off (-9.7%). Left field continues to be a tough field for home runs (30), but the friendlier confines of left-center has seen a dramatic increase from a home run factor of 60 to 100. Not surprisingly the deeper center field dimensions has led to a 27.9% decrease in home runs but what is surprising is that left-center and right field have played so differently despite their distances being nearly identical (+15.6% and -24.3%, respectively). One thing to note is that over the same time period last year Globe Life Park played as the 21 ranked offensive stadium but for the entire season it ended up being the 14 ranked park. It’s still too early to tell exactly how this park will play but it’s pretty evident that the new park is less friendlier to hitters than the old park.