Why Chase Field Matters

The quick read

Chase Field opened in 1998 as Bank One Ballpark, and the building was a first in baseball: a retractable roof over a natural-grass field. Phoenix summers run well past 100 degrees, so an open-air park was never an option. The answer was an airport-hangar-shaped building in downtown Phoenix with a roof that could close over the field and air conditioning that runs even when it is open.

The history packed into the place is short and loud. The Diamondbacks were born in 1998 and won the World Series in 2001, their fourth season, the fastest any expansion team has ever gotten to a title. They beat the three-time-defending-champion Yankees on Luis Gonzalez’s walk-off single off Mariano Rivera. Randy Johnson threw a perfect game here and won four straight Cy Young Awards in Arizona. The park lost its name in a bank merger, lost its hitter’s-park reputation to a humidor and a turf swap, took another run to the World Series in 2023, and in 2025 landed a renovation deal that keeps the team downtown for about another 30 years.

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The opening in 1998 and the BOB

Phoenix was awarded an expansion franchise, and the Arizona Diamondbacks began play in 1998. A traditional open-air ballpark does not work in Phoenix’s summer heat, so the team built something new: a stadium with a retractable roof over a natural-grass field, the first of its kind in baseball. The airport-hangar shape downtown was the practical answer to a climate problem, and the roof and the air conditioning have defined the building ever since.

It opened as Bank One Ballpark, nicknamed “the BOB,” on March 31, 1998. The Diamondbacks lost their first regular-season game 9-2 to the Colorado Rockies in front of 50,179, and the franchise drew more than 3.6 million fans in year one.

The 2001 World Series

In just their fourth season, the 2001 Diamondbacks won the World Series, beating the three-time-defending-champion New York Yankees four games to three. It was the first World Series to run into November, played in the shadow of the September 11 attacks earlier that fall.

The memory that defines the franchise is Game 7 at the BOB on November 4, 2001. Arizona trailed 2-1 in the bottom of the ninth against Yankees closer Mariano Rivera, the best in the game. With the bases loaded, Luis Gonzalez dropped a soft single over a drawn-in infield to score the winning run and take it 3-2. The title made Arizona the fastest expansion team ever to win a World Series.

Randy Johnson, Luis Gonzalez, and the early stars

Randy Johnson anchored those early teams. He won four straight NL Cy Young Awards in Arizona, threw a perfect game on May 18, 2004, and recorded his 4,000th career strikeout at the park that same year. His No. 51 is retired at Chase Field, and he entered the Hall of Fame as a Diamondback.

Luis Gonzalez, the 2001 hero and the franchise home-run leader, had his No. 20 retired in 2010. The park also hosted the 2011 All-Star Game, a marker of how quickly the new franchise and its building arrived on the national stage.

The name change and the humidor era

After the merger of Bank One and JPMorgan Chase, the ballpark was renamed Chase Field in September 2005. The BOB nickname stuck around with longtime fans for years after.

For its first two decades, Chase Field was one of the best hitters’ parks in baseball. The dry desert air, the elevation of about 1,059 feet, and a big outfield with deep angular corners all helped the ball carry. That reputation is now out of date, and the reason matters: the team installed a humidor in 2018, the second in MLB after Coors Field, and then switched from natural grass to synthetic turf in 2019. Storing the balls in controlled humidity took the carry out of them, and the two changes together suppressed home runs and offense enough that the park went from a launching pad to a neutral-to-pitcher’s park.

The 2023 pennant and the modern era

The Diamondbacks returned to the World Series in 2023, winning the National League pennant before losing the title to the Texas Rangers. The modern core is built around Corbin Carroll and Ketel Marte.

The 2025 renovation deal

The ballpark is publicly owned, by the Maricopa County Stadium District, and its lease was running out in 2027. To keep the team downtown, Arizona passed House Bill 2704 in 2025, and Governor Katie Hobbs signed it. The deal directs roughly $500 million in public money (recaptured sales taxes generated at and around the ballpark) toward renovations, with the Diamondbacks contributing about $250 million, for a total near $750 million. The money goes to the aging air conditioning and roof systems, a new scoreboard, and core infrastructure, and the agreement keeps the team in downtown Phoenix for about 30 more years.

A new 9,600-square-foot scoreboard, about 52 percent larger than the old one, was installed before the 2026 season.

Retired numbers

The Diamondbacks honor a short list of franchise greats with retired numbers: 20 (Luis Gonzalez, retired 2010), 51 (Randy Johnson, retired 2015), and 42 for Jackie Robinson, retired across all of baseball. The team also keeps a Ring of Honor for its other franchise figures.