Boston faces new hurdles

Ray Allen and Boston shot the lights out against the Knicks, but that's unlikely to continue in Round 2. Elsa/Getty Images

The first round isn't over yet, but several trends from the past have failed to hold so far. The Orlando Magic and Denver Nuggets, teams that appeared well-positioned for playoff overperformance (check out our East and West first-round trends), are clinging to life by a thread. Meanwhile, the New York Knicks' favorable pace of play couldn't help generate even a single win against the Boston Celtics.

In the grand scheme of things, one playoff round doesn't render irrelevant seven years worth of statistical correlation. However, it does provide a timely reminder of how the potential impact of a few key stats can easily be marginalized or negated entirely by randomness and other factors over four or five games.

Looking forward to the likely matchups in the conference semifinals, here's how some of the previous trends we found using data from TeamRankings.com could impact teams:

Despite an opening sweep, Boston is still vulnerable

With the only sweep of the first round, Boston made a statement against New York, but this season's Celtics still seem poorly equipped to make a deep playoff run. Beyond lacking a strong center and playing slowly, as we discussed previously, the Celtics had the lowest offensive rebounding rate in the league this year. Historically, that would mark them as possible playoff underperformers.

Admittedly, the C's managed to buck these same trends in 2010, but unlike Kevin Garnett did last year, neither Shaquille O'Neal nor Jermaine O'Neal seems likely to step up. Instead, the Celtics made it through the first round with 47 percent 3-point shooting, far above their regular-season average (and possibly a product of the Knicks' poor defense). Ray Allen showed in last year's NBA Finals that one good stretch of shooting doesn't necessarily carry over to the next game or series. In fact, previous trends suggest Boston could play more than two points worse than expected, meaning that it might take another stroke of luck from deep to get past the Miami Heat in Round 2 (assuming LeBron James & Co. advance past the Philadelphia 76ers).