(AP Photo/Alex Brandon)

The Washington Nationals trail Atlanta and Miami in the National League East and by and large have been pretty disappointing this season, most recently a 8-5 loss to the Miami Marlins in which they left 15 men on base and went 2-for-11 with runners in scoring position.

“It’s never easy to lose, and this stretch has been a tough one, but the attitude is there and it’s good,” Nats Manager Matt Williams said after his team suffered its sixth loss in seven games. “Unfortunately, we’re in the results business, so if the result is not what we want it to be, it’s not a good thing.”

The Nats had high expectations both internally and externally, including being picked by some to win the World Series before the season got underway, but they have been so far removed from the 2012 team that won 98 games in 2012 that Thomas Boswell questions if they even remember who they were back then.

Here are three reasons why the Nationals are not nearly as good as they were three seasons ago.

Their fastballs are much less effective.

Many pegged this pitching rotation — which includes Stephen Strasburg, Doug Fister, Jordan Zimmermann and Gio Gonzalez — to be one of the best in baseball. But instead, they have not been able to get much going with their high-speed pitches. In other words, their “stuff” stinks.

We can define pitch quality, or “stuff,” by using a combination of velocity and movement. A starting rotation with arms capable of throwing good “stuff” should have more success than those that don’t. The chart below shows the relationship between a pitcher’s speed on his fastball and the run value of the pitch expressed as “linear weights:”

A score of zero is average, with negative scores being below average and positive scores being above average.

In general, pitches will generally fall somewhere between +20 and -20 runs, with the most extreme pitches touching +/-30. On a per-100-pitch basis, the range shrinks to around +1.5 to -1.5 runs. Again, you’ll see some extreme scores on either end of the spectrum, but that’s the range that most pitches and pitchers fall into.

As you can see, faster fastballs are harder to hit, thus resulting in fewer runs.

Since 2012 the Nationals have lost some zip on their fastballs, going from an average velocity of 93.1 miles-per-hour in 2012 to 92.8 last season to 92.3 this year. As expected, the effectiveness has suffered.

They aren’t as lucky as they were in 2012.

When the 2012 Nationals scored 731 runs as a team and gave up just 594, they got help at the plate and on the mound. Their BABIP, which measures how many of a batter’s balls in play go for hits, was slightly higher than league average (0.308) while their BABIP against was significantly lower (0.282). Whenever a team or player has a high or low BABIP, no matter what the reason — defense, luck, or skill — it will eventually fall back down in line with the league or career average. And that’s exactly what we saw with the Nats.

Fewer flyballs leaving the yard

During the 2012 campaign the Nats hit 194 home runs, second-best in the National League; 34.6 percent of the balls batted in play were pop flies and 13.1 percent of those left the yard. This season just 9.7 percent go yard.

The magic of the 2012 season is long gone, and with the exception of pitching velocity, it’s largely out of the team’s control.