It was once said that the Battle of Waterloo was won “on the playing fields of Eton.” This reflected an understanding that the affairs of England and of the empire emerged from the rivalries and bonds and the habit of cooperation and clubbiness formed by elite schoolboys at play.

The documentary “Kick Like a Girl” (5 p.m., HBO) makes such a grand argument. Or maybe it does. This charming little home movie follows the Cheetahs, a girl’s soccer team from Salt Lake City, Utah. After two easy, unchallenging and undefeated seasons, their coach decided to let them compete in the boy’s league. She wanted them to face tougher competition and for them to experience losing. That would take awhile.

“Kick” is not merely a feel-good, you-go-girl story of triumph but an interesting look at the different ways that boys and girls approach practice, play and teamwork. While there are some adult voices and opinions expressed, most of the observations emerge from the mouths of both boy and girl players, aged 8 or thereabouts. Some still speak through their baby teeth with a child-like lisp.

And they have interesting things to say about how the Cheetahs won by planning, passing and teamwork, and how the boys often fouled up because some insisted on hogging the ball in order to stand out as a lone star. “They had one good player,” a Cheetah says of her vanquished adversary, “but he couldn’t do it alone.”

The boys make similarly insightful observations about how surprised they were when the girls took the field and transformed from “nice” to “mean.”

It would be interesting for the makers of “Girl” to follow the boy and girl players as they grow up and apply the lessons of the soccer field to high school, college and professional life.

• Kids compete on another field of battle as Tom Bergeron hosts the final round of “The 2009 Scripps National Spelling Bee” (7 p.m., ABC). Fans can catch the earlier rounds on ESPN (9 a.m. to 12 p.m., ESPN) and ESPN360.com from 12:15 p.m. to 5:15 p.m.

• Fans of a certain age may rejoice at the sight of the slightly venerable Eric Clapton and Steve Winwood performing together again on “Great Performances” (7 p.m., PBS, check local listings). Look for tunes from their 1969 Blind Faith collaboration and from their solo careers, as well as an homage to Jimi Hendrix, a contemporary “guitar god” who did not live to see his work become the stuff of “Great Performance” retrospectives.

• Who is America’s greatest salesman? Or is that saleswoman? “The Oprah Effect” (8 p.m. and 9 p.m., CNBC) examines Oprah Winfrey’s ability to endorse and embrace products from books to popcorn with spectacular results for companies large and small.

Tonight’s other highlights

• Earl makes amends with a wild man on “My Name is Earl” (7 p.m., NBC).

• The competition continues on “So You Think You Can Dance” (7 p.m., Fox).

• Grissom calls on Lady Heather on “CSI” (8 p.m., CBS).

• On two episodes of “The Office” (NBC), Jan’s big day (8 p.m.), bootlegged movies (9 p.m.).

• On two episodes of “30 Rock” (NBC), Liz confronts her high school demons (7:30 p.m.), Liz can’t face the holidays alone (8:30 p.m.).

• A missing paraplegic harbors a terrible secret on “Without a Trace” (9 p.m., CBS).