LITTLE ROCK — Checking a dictionary, fiddles and football, Bernstein and Bielema meld in the name of harmony.

The "H" word is defined as (A), the combination of simultaneously sounded musical notes that produce a pleasing effect and (B) agreement or concord. The definitions were confirmed after a speaker began a talk on humility by quoting Leonard Bernstein’s response when the world famous orchestra conductor was asked to identify the most difficult instrument to play.

Second fiddle, Bernstein said. "I can get plenty of first violinists, but to find one who plays second violin with as much enthusiasm or second French horn or second flute, now that’s a problem," he said. "And yet if no one plays second, we have no harmony."

He was talking about music; I’m talking about the relationship between Arkansas running backs Jonathan Williams and Alex Collins. Only one of them can start in Bret Bielema’s tailback-oriented offense and Williams has gotten the call the first two weeks. That’s only right — Williams has paid his dues and Collins is the newbie.

In two games, Arkansas has snapped the ball 144 times, including 104 running plays. Of those, Williams and Collins have 80 attempts. Somewhat surprisingly, the carries favor Collins 45-35. To be effective, Arkansas’ offense must get big plays from at least one of the two, preferably both. Against Samford, Williams set up the second touchdown with a 46-yard run and Collins’ gains of 21 and 55 set the table for two TDs. In the opener, Williams’ 75-yarder finally put away Louisiana-Lafayette.

After the ULL game, Bielema called Williams a "very, very gifted guy" who is going to "flourish in our type of system," and described Collins as a "guy that change the game in a single cut."

Based strictly on 2012, I have been more surprised by Williams’ production. He had limited opportunities last year and his best work was as a receiver vs. Kentucky. Before the season began, many thought Collins — one of the top high school running backs in the country last year — would be ahead of Williams on the depth chart.

My only complaint with Collins is the occasional attempt to make a big play when a couple of yards is the max. Samford tracked him down a couple of times on Saturday and there are better, faster defenses waiting in the Southeastern Conference.

Running backs coach Joel Thomas said the rotation of Williams and Collins involves a "little bit of everything."

Williams started the first two series in Little Rock, but Collins was on the field after a few snaps — a move precipitated by the heat and the desire to have fresh legs in the fourth quarter. During the final period, Arkansas ran for 170 yards, including 109 on 10 attempts by Collins and 36 on Williams’ six tries.

On the third series, Collins was first on the field. Williams scored Arkansas’ third touchdown and Collins the next one although his impulsive decision to celebrate with the fans did not sit well with Bielema. Thomas addressed the issue immediately and Bielema called it "inexcusable" early in his post-game news conference.

The fact that the head coach publicly laid down the law to a five-star recruit will not be lost on Collins’ teammates.

The trick is to keep both guys happy with their workload and, from here, that sure seems to be the case. It helps that the team is winning and both are getting the ball, but Bielema will handle the players if things go awry.

Alabama coach Nick Saban has done that for years despite carries tilted in favor of seniority. For example, Mark Ingram had 271 carries in 2009, the same year that freshman Trent Richardson ran 145 times. In 2011, Richardson was up to 283 attempts, while sophomore Eddie Lacy ran 95 times. Last year, Lacy had 204 carries and freshman T.J. Yeldon carried 175 times.