How big is the series against the Nationals for Orioles fans?

So another Orioles-Nationals series is here. It seems to me the rivalary is getting bigger and better in recent years with both teams contending for the playoffs. It's been a matchup of two good teams. The games have been well attended and a nice rivalry is developing.

The Nationals (46-38) are playing better with this three-game series set to begin. While they lost on Monday and Tuesday to Cincinnati before Wednesday's rainout, the Nats swept the Giants last weekend and are 12-5 over their last 17 games. During that stretch, Washington has outscored its opposition 68-37 and has a 2.13 team ERA.

The Orioles are looking for offense as they return to Camden Yards, where they are 26-16 for the season and 11-4 over their past 15 games.

After a torrid stretch of hitting with runners in scoring position, the Orioles have now been on an eight-game run with very few hits with RISP. From June 19-30, the Orioles hit .380 with RISP, scored 60 runs and went 7-4 in those 11 games.

But since July 1, they are batting .093 (5-for-54) with RISP, have scored 23 runs and went 2-6 in those eight games. Guess which team is in desperate need of a few clutch hits this weekend?

The Orioles have scored just 11 runs in their last six losses and 30 total runs while losing eight of 10 games. And they scored nine runs in one of those games. They scored eight runs in losing three straight at Minnesota.

This series features two of the best young talents in the majors in the Orioles just-turned 23-year-old Manny Machado and the Nationals 22-year-old star Bryce Harper.

Machado: .301 avg., 19 HRs, 48 RBIs, .360 OBP, .535 slugging, .895 OPS
Harper: .343 avg., 25 HRs, 60 RBIs, .471 OBP, .709 slugging, 1.181 OPS

Seeing Machado and Harper on the same field reminds me of the time I saw them bat back-to-back in the same lineup. Machado hit second and Harper third on June 21, 2011 at Single-A Delmarva's Perdue Stadium in the South Atlantic League All-Star Game. Click here to take a trip down memory lane from Machado's pregame interview that day.

Over his last 31 games, Machado is batting .371 with seven doubles, 11 homers, 15 multi-hit games and 25 RBIs. Machado has 13 homers his past 37 games.

While Max Scherzer has had a remarkable year and Jordan Zimmermann has been good too, the Nats rotation does rank sixth in the National League in ERA, and Washington is sixth in overall ERA in the NL at 3.58.

The Orioles are sixth in the American League at 3.74 but rank eighth in starting pitcher ERA at 4.18.

The Orioles have had the better of it in this series, winning the season series five times with two ties since 2008. The Orioles are 24-14 in that span, including a mark of 14-5 at Camden Yards. The Orioles are 10-4 versus the Nationals since 2012, and went 3-1 last year.

It should a fun weekend with big and enthusiastic crowds at the Yard. How big has this rivalry become for Orioles fans?