Meet the true X-factors in this World Series: The roofs

MILWAUKEE – Look up during the World Series and you’ll see the roofs at American Family Field and Tropicana Field. There’s a chance this could be the first World Series played entirely indoors. And there’s a chance that a ball striking one of those roofs -- or the supporting structures, in The Trop’s case -- could impact one of the games.

They are not just green steel in Milwaukee and white polytetrafluoroethylene-coated fiberglass membranes hanging above four rings of catwalks in St. Petersburg. They are potential supporting characters.

Heck, one of them has its own phone number; in Milwaukee, you can call the American Family Field Roof Hotline -- (414) 902-4636 -- and hear a recorded message about the roof status for that day’s game. It’s a handy tool for fans getting dressed for a night at the ballpark.

With the temperature expected to be right around 60 degrees for the first pitch of Games 1 and 2 in Milwaukee, according to the National Weather Service, the roof will probably be closed. When the World Series moves to Tampa Bay for Games 3 and 4 (and Game 5, if necessary), there’s no option for it to be open.

And if that comes into play, it would not be the first time this season.

The Brewers were thanking their stars for the roof after Game 1 of the NLDS against the Padres. In the most bizarre ending imaginable, the Brewers won, 3-2, after Ty France's potential go-ahead home run hit a roof cable or support high over deep left field and landed in Jackson Chourio’s glove in left field for the second out of the ninth inning.

Where the ball would have landed had it not been obstructed remains open for debate. Brewers manager Pat Murphy and third baseman Joey Ortiz, who each had the right angle, insist it was heading foul. The Padres, though, couldn’t help but wonder what might have been. ​

If you knew the ground rules, you knew it was an out.

Here’s the language in the Milwaukee media guide:

ROOF AND CABLING
In play: Ball strikes roof, roof truss or roof cable over fair territory. (If caught, batter is out and runners advance at own risk.)

Dead ball: Ball strikes roof, roof truss or roof cable over foul territory.

Foul: Ball strikes roof, roof truss or roof cable over fair territory and lands in foul territory

Fair: Ball strikes roof, roof truss or roof cable over fair territory and lands in fair territory

San Diego challenged the ruling, hoping the ball had hit the cable in foul territory (thus rendering it a dead ball). But after a brief review the call stood. France was out. The Brewers won.

“I came in here and said, ‘Incredible home-field advantage,’” said Brewers third-base coach Matt Erickson, who actually, incredibly, predicted that very moment during a pregame lineup exchange caught by cameras.

It doesn’t happen often.

During the sixth inning of Game 4 of the 2008 NLDS, Philadelphia’s Jayson Werth hit a fly ball that seemed headed for left field, but hit the truss and headed downward toward the infield. Brewers third baseman Craig Counsell made a terrific diving catch.

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And in April 2018 against the Reds, Cincinnati’s Scooter Gennett hit a fly ball to right field that hit a truss and fell into the glove of Brewers second baseman Eric Sogard for an out.

There have been other instances of foul balls. But those three are the only known instances of a baseball hitting the roof in fair territory during a game.

Tropicana Field -- which had to be fully repaired after the roof was ripped off during Hurricane Milton two years ago, forcing the Rays to play a season outdoors at George M. Steinbrenner Field across the bay in Tampa -- presents a different set of circumstances, obstacles and ground rules.

Anyone who’s watched a game in the Rays’ domed home knows that the artificial turf can create tricky hops. Unfamiliar outfielders occasionally struggle to spot a white baseball against a white roof. And when a ball gets up near the four rings of catwalks supporting the structure, well, it’s time to break out the rule books.

Let’s break it down.

The four catwalks located above the playing surface are labeled, in order from highest to lowest, the A-, B-, C- and D-rings. Any fair ball that hits the lower two catwalks (C-ring and D-ring) is a home run. A fair ball that hits either of the top two catwalks (A-ring and B-ring) is in play. Any fair ball that stays on one of the top two catwalks is a ground-rule double. Finally, any foul ball that hits one of the catwalks is a dead ball.

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You might be surprised by how often this comes up. According to the Rays’ media guide, 200 fair balls had hit the catwalks entering the 2026 season. Five fair balls have hit catwalks in the postseason -- all of them home runs, with the most recent being Nelson Cruz’s shot off the C-ring in Game 1 of the 2021 ALDS.

It came into play in a different way in Game 2 of this year’s ALDS, when the Yankees’ Spencer Jones hit a high popup into shallow right-center field that hung in the air for 10 seconds and clanked off the B-ring before landing in right fielder Victor Mesa Jr.’s glove for an out.

Speaking of the roof, it’s also helpful to know the rules about opening and closing the dome during the Milwaukee portion of the World Series.

For ballparks with retractable roofs, the decision to begin the game with the roof open or closed rests with the home team during the regular season. But, per MLB rules, “during the postseason, the Commissioner or another designated official shall make all decisions regarding roof movement, in consultation with the home club and the umpire crew chief.”

Typically, the cutoff for open versus closed in the regular season is in the 60-65 degree range. At Tropicana Field, of course, it’s always 72 degrees under the tilted roof.

If the verdict is “closed” for each Milwaukee game, this World Series would be the first played entirely indoors. Globe Life Field hosted the entire neutral-site World Series featuring the Rays in 2020, but the roof was open for Games 1, 2 and 4. The Rangers and D-backs met in the 2023 Fall Classic, and both play in domed homes, but Chase Field’s roof was open for Games 3-5 in Phoenix.