In the zone? C's test defensive switch

AP Photo/Lynne Sladky

Will the Celtics mix in some zone in hopes of slowing Miami's layup line?MIAMI -- The Boston Celtics own the best half-court man-to-man defense in the playoffs, but coach Doc Rivers sampled a zone look during the fourth quarter of Monday's Game 1 loss and suggested more might be coming.

"You'll see it," Rivers said of the zone. "We like it. As a coach, you get kind of caught. We've been working on zone all year, even though we've played it probably five or six times all year. We work on it every practice. We go through it every shootaround. We believe it will be effective in this series. But when you're down 16 or 18, you're kind of caught, do you use it for wait for the next game, or do you show it and try to see what they run and then make adjustments to it? And that was the final decision we made. At that point, when we ran it, I didn't know if we were going to make a run. I was trying to see really how we could tweak it to make it better."

According to Synergy Sports data, the Celtics went to zone five times during a three-minute stretch early in the fourth quarter of Monday's Game 1. The Heat responded by taking the bait and missed five 3-pointers on those five possessions. Given the way the Heat scorched Boston around the basket to open the Eastern Conference finals, Boston was content to let them fire away from the perimeter and utilize the zone to clog up the paint a bit.

The question is whether Miami will settle like that when it doesn't have a double-digit cushion to fall back upon. Or if the Celtics can expect the Heat to miss the sort of wide-open opportunities that existed on those possessions.

Boston utilized a zone defense a mere 3.7 percent of total defensive possessions during the 2011-12 regular season, according to Synergy. While it often initially worked as a gimmick -- it helped Boston rally from a big hole in Miami very early in the season -- teams often found ways to eventually exploit it.

The key is knowing when to activate the zone and when to get out. After all, the numbers don't suggest overall success. While Boston's half-court man-to-man defense was the best in the league this year (0.809 points per play), the zone defense ranked just 14th (0.929 points per play).

In the playoffs, Boston is allowing a postseason-best 0.796 points per play in man-to-man half-court situations, according to Synergy. Boston has only utilized zone on nine possessions overall this postseason, allowing a mere six points (0.667 points per play) on 2-of-8 shooting (25 percent; the Hawks made a pair of 3-pointers). That's not a big enough sample to determine if the zone is worthwhile, but given Boston's health woes and inability to truly match Miami's individual athleticism, it might be one of the Celtics' only options if the team struggles to keep Dwyane Wade and LeBron James from attacking the basket.

But Boston has to tread carefully. The numbers also suggest that the Heat were more successful against zone during the regular season, averaging 1.007 points per play in a small sample (5 percent of the team's total possessions in the half-court set), compared to 0.903 points per play out of man-to-man coverage.

"Rebounding and individual defense is huge in zone," said Rivers. "I thought the game earlier in the year when we played them... our zone was effective, but they scored on us off of dribble penetration. Just because you're in a zone, you still have to guard the ball. And then the long rebounds."

The Celtics have struggled with both denying dribble penetration and chasing down long rebounds this season. It's the reason the zone will likely remain more of a changeup than something Boston will lean on to turn around this series.