A New Ballpark Can't Hide Mismanagement: Measuring Fan Engagement in New MLB Stadiums

In Part 1, I predicted Oakland A’s attendance in a hypothetical new ballpark.

In Part 1b, I look at MLB teams with actual new ballparks and predict attendance if they had hypothetically stayed in their old ballpark.

Teams build new stadiums to mobilize fans and generate excitement. Some teams use their new stadium to engage fans far more effectively than others.

In Part 1, I attempted to measure a “new stadium effect” independently from fan engagement. I essentially hard-coded fan engagement into the model. For example, from 2007-2011, the A’s were actively seeking to move away from Oakland. Fan engagement was very poor, and my predictions for a new stadium in 2008 took that into account.

This is because I had no way to predict how fan engagement would improve with a new stadium.

But there is a way to retrospectively measure this: why not look at teams with new stadiums and compare attendance to what it would be with fan engagement at a fixed, baseline level?

There is a huge advantage to the second approach: we can now measure how fan engagement changed with the new ballpark by comparing actual attendance to predicted attendance. And it quickly emerges that there are three scenarios when a team opens a new ballpark:

  1. High fan engagement: They capitalize on the new ballpark by winning, producing a long run of seasons with high attendance.

  2. Medium fan engagement: a middle of the road scenario where there is clearly a benefit from the new stadium, but not a huge one.

  3. Low fan engagement: they whiff on the opportunity by fielding a terrible team, alienating fans within one season.

Thinking of recent new stadiums, the Giants, Phillies, and Twins generated high fan engagement with AT&T Park, Citizens Bank Park, and Target Field. The Padres and Pirates generated medium fan engagement with Petco Park and PNC Park. And the Mariners, Mets, and Marlins have generated little positive to negative fan engagement after opening Safeco Field, Citi Park, and Marlins Park.


As described in Part 1, my model for predicting MLB attendance has the following parts:

  • On-field performance data: runs scored, games back from first place, Elo rating, win probabilities, etc.

  • Weather data: average wind speed, average temperature, low temperature, high temperature

  • Location data: stadium age, capacity, metropolitan area population

  • Team+year/fan engagement effect: Having a team and year variable allows for a “team+year” effect that is akin to fan engagement. This may be influenced by long-term performance of the team, the economy, and popularity of baseball in general. The fan engagement effect measures how attendance responds to on-field performance and weather—elasticity of demand. Are fans more willing to come out for a mediocre team on a cold night? Also can be thought of as fan excitement/stoke.

For this analysis, I used the same model as Part 1 with one change: I trained the model on 1990-2018 data instead of 1995-2018 data. This allowed the model to have more training data for the old stadiums.

I kept fan engagement fixed by setting the “year” variable to the year before the new stadium opened.

For the Giants, AT&T opened in 2000. So all game and weather data for the Giants from 2000 to 2018 was used but labeled as “1999.” This is the baseline period. Additionally, I set the stadium to “Candlestick Park” and set stadium age and capacity accordingly. Then I used this dataset for prediction.

Low Fan Engagement

We’ll go from lowest fan engagement to highest. The Mets come in dead last. Part of this is luck; the Mets had their highest attendance the year before Citi Field opened. People came out in droves in 2008, but the Mets collapsed down the stretch and were bad in 2009. Fans and players alike complained about the “cavernous” dimensions of the park. It was a bad start. The model thinks fan engagement is worse than 2008 and I don’t think many people would argue.


Next we have the Mariners. They have been absent from the postseason since 2001, the longest playoff drought in baseball. Safeco Field is beautiful and conveniently located in downtown Seattle, yet fans aren’t willing to show up or invest their time in the team because of the many years of disappointment. Fan engagement is now worse than it was in 1999, when there was at least the promise of a new ballpark.

This means if the Mariners had played their 2018 season in the Kingdome and fans were as engaged/excited as 1999, they would have drawn more fans.


The Marlins are the last low engagement team. Although their stadium is only four years old, attendance in 2018 is abysmal. The team was sold in 2017 and the new ownership subsequently traded many of their best players. The team is tanking, and fans aren’t showing up. The new stadium can’t stop the plummet.


Medium Fan Engagement

I consider the Padres and Pirates to have generated medium fan engagement with Petco Park and PNC Park.

The Pirates drew huge crowds at PNC Park in its first year, but the on-field product was terrible in the second year. In general, attendance at PNC Park is slightly higher than it would be at Three Rivers Stadium, using a fixed 2000 baseline for fan engagement/excitement. However, PNC Park is frequently considered to be one of the best—if not the best—ballpark in MLB. The Pirates have failed to capitalize on their gem.


The Padres are probably the middle-of-the-road case for a new ballpark. The Padres have had a few very bad years, but are usually an average baseball club. They have also been slightly above average at times. Likewise, Petco Park has helped them increase attendance and fan engagement, but not as much as the teams in the next section.


High Fan Engagement

Lastly, we have the best case scenario: new stadium plus winning and championships. That’s the Giants and the Phillies.

The Phillies were a powerhouse in the late 2000s and won the World Series in 2008. Citizens Bank Park was packed in those years. While they had a rough streak, they are once again interesting and attendance is on the upswing. Interestingly, their previous ballpark, Veterans Stadium, showed that the Phillies could draw crowds in the mid 1990s. The model thinks the Vet could have drawn similar crowds in the late 2000s as well, but not as big as the crowds that showed up in Citizens Bank park.


A’s fans, myself included, now consider the Giants to be an arch-rival. They built a classic, beautiful stadium by the water in San Francisco in 2000 and instantly drew sold-out crowds. They had the Barry Bonds show for the early 2000s and a National League Pennant in 2002. Then they won the World Series in 2010, 2012, and 2014. Now they are an attendance juggernaut even though their on-field product was very, very bad in 2018.


I hate to say it, but the transformation achieved by the Giants in AT&T Park blows all the other stadiums out of the water. They have the best fan engagement of all the teams to build a stadium in the past 20 years.

If I were the A’s, I would study all of these examples closely. There’s a mix of ballpark qualities, winning, location, and timing that leads to these different outcomes. Since the A’s are privately financing their stadium, they may particularly want to study Citi Field, Safeco Field, and Marlins Park. From an attendance and fan engagement perspective, those stadiums did not warrant the investment.