Success on the field has not translated to success at the box office for D.C. United. (Getty Images)

Things are looking up for D.C. United, which has won three straight and is closing in on its first MLS playoff berth in five years. Off the field, however, United continues to struggle at the box office. Barring an enormous turnout for the regular season home finale Oct. 20, the club will post its lowest average attendance at RFK Stadium since MLS launched in 1996.

At 13,483, United is 17th out of 19 teams in a league on pace (18,531) to record the highest attendance number in its history. Previous MLS high marks were 17,872 last year and 17,406 in the inaugural season.

United has experienced an 11.1 percent drop since last season and a staggering 32 percent fall since 2008, when it drew an average of 19,835. Over the same four-year period, MLS’s overall figure has risen 12.6 percent, buoyed by strong support in five expansion cities: Seattle, Portland, Vancouver, Philadelphia and Montreal.

After surpassing the league average for 12 consecutive years, United’s attendance has been below MLS’s standard each of the last four seasons.

As one of the league’s original teams – eight have played every year since 1996 – United is susceptible to cycles. Despite the recent drop, D.C. remains one of the best draws in MLS annals, having entered this 17th season with an all-time average of 17,194. The only founding member to top that is the Los Angeles Galaxy. The league figure between 1996 and 2011 was 15,745.

Recent additions to the league have not been around long enough to experience attendance fluctuation (although Toronto’s woeful short history is beginning to catch up with it).

That said, United’s numbers this year are glaring. Seattle’s average of 42,134 is more than three times larger than D.C.’s.

MLS celebrated one of its best single days ever last Saturday, averaging 25,088 in six games. The range was 19,172 in Chicago to 38,948 in Seattle. The next day, while Philadelphia drew 17,666 and Vancouver attracted 18,992, United announced 11,770.

There is no single explanation for D.C.’s dreary numbers. Rather, several factors have contributed to the four-year fall:

*No playoff appearances since 2007. The team is much improved this season (15-10-5, tied for third place in the Eastern Conference), but casual fans are typically slow to warm up to a winning side. (The Washington Nationals are among baseball’s best but rank 14th out of 30 teams in attendance. The playoff-bound Baltimore Orioles are 22nd.)

As you will see in the chart below, United’s highest attendance was in 2001, when a bad club benefited from the attendance carry-over of winning teams in the early years.

*No international superstars. United has several high-quality players (most notably, Dwayne De Rosario and Chris Pontius) but no one with the mainstream drawing power of England’s David Beckham (Los Angeles Galaxy) or France’s Thierry Henry (New York Red Bulls).

*An old stadium with no amenities. RFK (age 51) has heart and soul … but run-down restrooms, few amenities and low-angle sightlines built for baseball.

A new stadium promises to have a major impact on DCU attendance. Just look at what happened in Kansas City, which lacks Washington’s diversity and soccer history. The club didn’t draw well at oversized Arrowhead Stadium and then played at a small, minor league baseball park while a venue project came to life. Since Livestrong Sporting Park, a gorgeous suburban facility, opened last year, the club has seen average attendance grow to 19,296 this season.

United has proposed building a medium-sized facility at Buzzard Point in Southwest D.C., about four blocks from Nationals Park, but a deal with developers and the city still appears a ways off.

*RFK is too large to create ticket-buying urgency. Why purchase in advance when, even with “reduced” capacity, you can wait until the last minute whether to attend?

*Prices for individual tickets. Purchased on gameday, a decent sideline seat in the lower bowl is $32.

*The season ticket base has eroded. Several mediocre and poor campaigns in a subpar venue prompted fans to cancel packages, so United’s starting point before each game is much lower than in previous years. A good walk-up fails to compensate for the loss of once-reliable attendees.

*Unfavorable scheduling. United played nine home matches in the first 2 ½ months, then two over almost the next two months. Four games were set in August – when Washingtonians flee for the Outer Banks – and two of those four were mid-week, when many MLS teams have a hard time selling tickets.

Under new East vs. West scheduling, the defending champion Galaxy, featuring Beckham and Landon Donovan, didn’t visit RFK this year. And the two matches against archrival New York were played on a late-day Sunday and a Wednesday in August for TV purposes. Only nine of 17 home dates were on Saturday nights, United’s sweet spot.

*Budget. Until deep-pocketed investor Erick Thohir joined managing partner Will Chang this summer, United didn’t have the marketing muscle to compete in a region that includes two NFL teams, two Major League Baseball teams, NBA and NHL franchises, and several prominent college athletic programs.

United’s attendance numbers through the years…..

1996: 15,262 (7th of 10 in MLS). League average: 17,406

1997: 16,698 (4th). League: 14,619

1998: 16,007 (5th of 12). League: 14,312

1999: 17,419 (3rd). League: 14,282

2000: 18,580 (2nd). League: 13,756

2001: 21,518 (1st). League: 14,961

2002: 16,519 (6th of 10). League: 15,822

2003: 15,565 (6th). League: 14,898

2004: 17,232 (2nd). League: 15,559

2005: 16,664 (5th of 12). League: 15,108

2006: 18,251 (4th). League: 15,504

2007: 20,967 (2nd of 13). League: 16,770

2008: 19,835 (3rd of 14). League: 16,460

2009: 15,585 (7th of 15). League: 16,037

2010: 14,532 (11th of 16). League: 16,675

2011: 15,181 (11th of 18). League: 17,872

2012: 13,483 (17th of 19). League: 18,531