Why Matt Barnes and Vince Carter Will Cross-Match against Paul Pierce and Ray Allen

After the Orlando Magic's practice today, during which they prepared for the Eastern Conference Finals against the Boston Celtics, small forward Matt Barnes raised some eyebrows when he told the media that he would begin the series covering shooting guard Ray Allen, leaving Vince Carter to cross-match on Paul Pierce. As Tania Ganguli points out in her Tweet, that's a departure from the regular-season series, in which Barnes covered Pierce and Carter took Allen. So why the switch?

On the surface, it doesn't appear to make much sense. Barnes defends better than Carter does, while Pierce is a more dangerous offensive player than Allen in that he's better capable of creating his own shot. That's not to say that Allen is, I don't know, Jason Kapono or something. But Pierce is the more versatile offensive player.

Zach Lowe of CelticsHub tries to sort through it:

Having Barnes chase Ray Allen around saves Carter’s stamina, which he needs to effectively play his role as one of Orlando’s two primary ball-handlers on offense. Both Carter and Barnes are listed at 6′7", so height isn’t an issue. Neither is as fast or quick as Ray, but perhaps Stan Van Gundy believes Barnes’ long arms can help him contest Ray’s shots even if he can’t quite keep up around every single Boston screen.

And as he points out via email, Carter "perked up this season when he ended up on Pierce," so there's also that to consider. Lowe is probably onto something here.

I consulted Synergy Sports Technology to better understand why, exactly, Van Gundy has chosen to make this switch.

I suspect Van Gundy, who's big into advanced metrics and scouting, may have had a look at these numbers, or something very similar, because they indicate he's made a pretty sound move here.

First, let's consider Pierce. Again, his skill and versatility make him a tough cover, which is why it seems a bit odd that Barnes won't get the assignment at first. But here's a look at how Pierce got most of his offense this season, and how Barnes has defended each of those play types:

Pierce gets post of his offense initiating the pick-and-roll, which happens to be Barnes' biggest weakness defensively. He's also not much of an isolation defender. His biggest strength, covering players coming off screens, also happens to align with how Allen gets most of his offense:

So Barnes on Allen--or, if you prefer to word it differently, Barnes off Pierce--makes sense, though the low frequency with which he's had to cover shooters coming off screens might be cause for concern. But what of Carter? Can he hope to cover Pierce? The answer appears to be "yes." Here's how Carter covered the pick-and-roll and isolation plays this year. Refer back to the first chart to see Pierce's execution of those plays:

So although Barnes is a better defender overall, Carter's skill set better equips him to cover Pierce. And Barnes' tools counter Allen's quite nicely.

Basketball, to use a cliche, is not played on paper. The teams decide the games on the court. Maybe this analysis will ultimately prove invalid. But based on the season-long performances of all four players in question, Van Gundy appears to have made an excellent move here. We'll see how everything plays out this Sunday, and over the next two weeks.