With Manny Machado playing third, Baltimore's first base platoon (at least for now) is Wilson Betemit and Mark Reynolds. Betemit will be starting against RH pitchers and Reynolds against lefties.
This year, hitting from their best sides of the plate, those two guys' combined offensive numbers read like this:
358 plate appearances, 318 AB, 94 hits, 23 doubles, 13 homers.... .296/.369/.491.
Mark Teixeira has had 93 more plate appearances (451). He's hit 23 doubles and 22 HRs but his hitting line is .257/.337/.491 this year.