The outfield seats at AT&T Park are split up into Bleacher seats in left and center field and Arcade seats in right field.

Sections 136-144 are bleacher-style seats with no backs, though the last row in each section backs up to a railing which you can lean back on.

Sections 145-152 in the Arcade are also bleacher style (metal) seats, but they also include back support.

Note the bleacher-style seating with backs in the AT&T Park Arcade seats