Thr Orioles currently have two relievers in the top 10 of groundball percentage. Essentially they have two pitchers most likely to produce a groundball when it is hit. The two pitchers are Brian Bass and Cla Meredith who rank 7th and 8th respectively. Cla Meredith is, I believe, the pitcher who came over from the Oscar Salazar trade. If so, the Orioles have gotten a more valuable bullpen arm then first believed. Interestingly there's a third Baltimore reliever who's among the top 20, coming in at 12th in GB%. Danys Baez has a GB% of 59.6 %. Together this triumvirate are helping to lead the Orioles to first in reliever GB% with a team rate of 50.2%.
Brian Bass, former Royals farmhand (really!) and Twin, current Baltimore longman has become a useful bullpen arm. His move to the bullpen has allowed him to K more batters, but unfortunately walk a few more too. This year Bass has decreased both his FB% and his line drive rate converting both to groundballs. This has led to a 2.78 GB/FB ratio and an increased GB rate. The biggest change pitch-wise has been a move towards using his curveball more often at the expense of his slider and horrific change. All his pitches have more vertical drop than last year although it's worth noting that 3.6% of his pitches are considered unknown. Brian Bass still needs some more work, but he may just need to have a better defensive infield behind him (this year according to UZR or Ultimate Zone Rating the Orioles have had subpar defensive seasons from every infield position but shortstop. Also Wiggington compares favorable at every infield position except 3B presumably due to small sample size)
Cla Meredith apparently has a good sinker and change according to the scouting report available at SB Nations. While his GB% is rather high it has decreased the past three years from an unsustainable high in 2007. This may be the case of batters figuring out a pitcher or of skills decreasing. It's more likely a combination of the two as his strikeout rate has decreased while he has started to walk more players. Hopefully part of this is reveresed as he faces off aginst players who haven't seen his stuff. Part of his problem may be that his changeup has ceased to drop as much losing three inches of vertical drop. Hopefully it may be a mechanical problem that can be corrected quickly.
Danys Baez is a well-known player to Baltimore's fans, although I think most were hoping he would get traded. Currently his K/BB is at 1.63, better than last year's abomination of 1but near his other career lowpoints. With that low a K/BB Baez would normally be just a poor middle reliever. The key to this years success has been his GB% which has moved from a previous high at 51.2% last year to 59.6%. With this his GB/FB ratio has moved to 2.22, a rather elite number