Safeco Field (Seattle)
Safeco Field Ground Rule Particulars


Fair bounding ball striking the portion of the wall that is recessed above the padded outfield wall: Out of Play, Two Bases.

Netting in right field corner in foul territory is above and beyond the wall. A batted ball that bounds into the netting is a dead ball whether or not it rebounds onto the playing field: Two Bases.


Batted ball strikes roof truss over fair territory: In Play.
    • If caught by fielder, batter is out and runners advance at own risk.

Batted ball strikes roof truss over foul territory: Dead Ball.


Please refer to Commissioner's Bulletin regarding opening and closing of retractable roofs.



The Club President, after consultation with stadium operations personnel and the Head Groundskeeper, shall determine the roof configuration for the start of the game. In his absence, a joint decision will be made by the VP of Ballpark Operations, VP Associate General Manager and Head Groundskeeper.

The following factors will be considered when determining whether the roof shall be open or closed at the start of a game, always keeping in mind that Safeco Field is considered an “outdoor” facility.

1. Fan comfort and their enjoyment of the game.
2. Current weather conditions (rain, temperature/wind).
3. Weather forecast for throughout the game.

While there shall be no definitive temperature standard used to determine roof closure, less than 50 degrees at field level is generally considered uncomfortable for our fans. Under those conditions, particularly if there are threatening skies, closing the roof is a recommended policy.


The guidelines spelled out in MLB’s 2009 Bulletin D-16 shall apply to roof movement during games at Safeco Field with the exception of Paragraph B (Opening a Closed Roof): It is the policy of the Mariners that if a game starts with the roof closed, or if the roof is closed during the course of a game, it shall remain closed for the duration of the game.

It is also the policy of MLB and the Mariners that should it start to rain in the middle of an inning, the roof can be closed during play after proper consultation with the crew chief and the visiting club. There is no need to wait until the end of the inning.

Universal Ground Rules:

The Commissioner’s Office has issued the following Universal Ground Rules for use in all Major League ballparks this season. Ground Rules pertaining to individual parks are posted separately in those parks.