How many domed MLB stadiums are there?

Answer 1

Currently, there are three if you include Toronto's Rogers Centre, which has a retractable roof. They are the Hubert H. Humphrey Metrodome, home of the Minnesota Twins (sadly no longer their home after 2009), Tropicana Field, home of the Tampa Bay Rays, and Rogers Centre, home of the Toronto Blue Jays. Former domed stadiums are the Astrodome, home of the Houston Astros from 1965-1999, Olympic Stadium, home of the Montreal Expos from 1977-2004, and the Kingdome, home of the Seattle Mariners from 1977-1999. Correct me if I'm wrong.

Answer 2

There are 7 stadiums that have the ability to be "domed".

Stadiums with a fixed roof:

Tropicana Field -Tampa Bay Rays

Stadiums with retractable roofs:

Chase Field - Arizona Diamondbacks

Rogers Centre - Toronto Blue Jays

Safeco Field - Seattle Mariners

Miller Park - Milwaukee Brewers

Minute Maid Park - Houston Astros

Marlins Park - Miami Marlins

Side Note: The Minnesota Twins used to play at a fixed roof stadium, the Hubert H. Humphrey Metrodome. However, they have since built a new outdoor ballpark, Target Field, which they have played in since 2010.