The league average rate is 11.4% of runner on first base with less than two out being involved in a double play. The Orioles' value for this metric is 15.7%, which is 38% greater than the league average and 2.42 standard deviations away. The Braves are 23% less likely to ground out in a double play than the league average with a rate of 8.7%. This story has remained relatively consistent through the first two games of the three game series with the Orioles leading the Braves 5 to 2 in GiDPs.
What is interesting is trying to figure out why the Orioles are much more proficient in inducing these than Atlanta is. First off, both teams hit about the same amount of ground balls with the Orioles having the 13th highest rate in baseball and the Braves with the 16th highest rate. If you put any stock in Speed Scores, the Orioles have the least team speed in baseball and the Braves are average. However, a comparison of speed score with GiDP does not yield much. For instance, the second slowest team in baseball according to this metric, the Red Sox, have the second lowest GiDP rate. Fangraphs Base Running metric also does not yield much as the Orioles rate as average and the Braves rate are a fringe first division team on the base paths.
J.J. Hardy has the most GiDPs on the team with 11. He actually hits fewer ground balls than a league average hitter. He has always had a variety of players bat in front of him who are not exactly slow (Endy Chavez - 19 times; Nolan Reimold - 14; Robert Andino - 13; Xavier Avery - 11). Hardy appears to be having bad luck. He is on pace to shatter his previous mark of 18 GiDP in a season. I expect him to do better in the future.
The next two players on the Oriole leader list I am less sure about. Adam Jones is second with 9 GiDPs. Half of his hit balls are grounders and he has had Hardy and Nick Markakis in front of him (not exactly burners on the base paths). Third is Andino with 8 GiDPs, which may result from half of his hits being ground balls and having players like Luis Exposito and Chris Davis bat in front of him.
The Orioles propensity of GiDP may simply be due to lineup construction and the specific attributes of the team's star players. The Orioles have a number of good players who happen to be unlucky or simply have a greater chance for ground balls. When this is combined with other good players on the team not having good speed, it can result in a heavy GiDP situation. The Braves on the other hand have a burner in Michael Bourn and players like Dan Uggla, Freddie Freeman, and Brian McCann who simply do not hit ground balls (33%, 35.2%, and 38%).