After two games against the Grizzlies it seems Matt Bonner has leapfrogged Boris Diaw as the third big and not everyone is happy about it. Bonner is better than he gets credit for as a defender and rebounder, but Diaw is just as good and brings a more versatile skill set than the Red Rocket. But Pop has chosen Bonner so far and, at least in my eyes, he's made the right decision. Here are the reasons why.
The Spurs' defensive game plan hides some of Bonner's flaws
The Spurs choose to guard Zach Randolph by fronting him in the post while sending help from the weak side. The key for it to work is to beat Z-Bo to his spot and hold your ground, which means discipline, anticipation and speed are just as important as strength. Both Diaw and Bonner are good at fronting the post player and rarely get caught out of position. Diaw has arguably the strength advantage but Bonner is longer and would make an entry pass more difficult to execute, so neither gets the edge there.
Randolph is not going to attack off the dribble from the perimeter, which is a move Diaw defends much better than Bonner, and the Spurs can live with him taking outside jumpers. And as opposed to what happened against the Warriors, the Spurs don't want to switch on the perimeter or even send one of their bigs outside to contest mid range-shots most of the time. So Bobo has nothing to separate himself from Bonner on defense. How about rebounding?
Diaw doesn't significantly help the team on the defensive glass
During the regular season, when Boris Diaw was on the court, the Spurs grabbed 72.6% of available defensive boards. With Matt Bonner playing they grabbed 74.6% which is very, very close to their overall average. Individually, they are both underwhelming but comparable rebounders, with Bonner barely edging out Diaw.
Against the Grizzlies in the regular season, Diaw fared much better, with the Spurs grabbing 79.5% of all available defensive boards. Per 48 minutes, with Bonner on the court, they just pulled down 67.3% of defensive rebounds and the Grizzlies scored 15.4 second chance points to the 9.5 they got when Diaw was in. So it seems Diaw helps negate one of the Grizzlies' strengths. But in the playoffs that gap hasn't appeared and both guys and the team in general are doing a great job so far of preventing the Grizzlies from both getting a high percentage of available offensive boards and from scoring second chance points.
No one will keep the Grizzlies off the offensive glass completely but right now having Bonner out there is not hurting the Spurs and, considering he is not a great individual rebounder, having Diaw out there likely wouldn't tip the scales to the Spurs' favor. So it comes down to offense.
Diaw is not a stretch four
After he was a valuable part of the team last season, the idea was for Diaw to be the third big, pairing up with two inside scorers in Duncan and Splitter. That would help balance out the offense for the second unit and especially for the spread pick-and-roll reliant Manu Ginobili. Spacing is a key ingredient of a good offense and the Spurs were counting on Diaw to provide it while also adding an all around game that Bonner couldn't bring to the table.
The problem is teams simply do not respect his shot, which is understandable since he's taking less than one three pointer a game in the playoffs after taking only one three pointer on 22.8 minutes in the regular season. Just like the Spurs play off Tony Allen, the Grizzlies will play off Diaw if he is behind the arc trying to space the floor for a pick and roll or a post up. That allows the opponent to simply pack the paint, prevent the Spurs from running their offense and force them to take a low percentage shot. It happened all throughout the season and it will happen again and again until Boris takes and makes three pointers consistently.
It's not really his fault. The Spurs use him in a role that is not the one he is best suited for. He is at his best when he can facilitate for others, not try to finish plays. Diaw would be valuable as an escape valve if the Grizzlies were aggressively trapping Parker, but they aren't. And with the stout Grizzly post defense, he can't take advantage of smaller or lighter players in the post.
Meanwhile, Bonner always forces a big to come out and, if he's the screener, will usually either force a switch or get an open three point look. What Matt needs to do is hit those shots or the runners that result from aggressive closeouts. If he does, he becomes a much better option than Diaw for the Spurs in this series despite being a significantly more limited player. And that's why Pop has been playing Bonner more than Diaw.
The Blair option
Since Diaw doesn't seem well suited to play against the Grizzlies and Bonner's shot is the only thing that makes him a good option, would playing DeJuan Blair make sense? At first glance, it doesn't. Blair has no outside shot to speak of and he would struggle mightily to score on Gasol or Randolph with his limited post moves. Defensively, he is good at fronting but he usually waits until the post player establishes position and goes for the steal instead of beating him to the spot.
His rebounding would help make the best case for him to move past any of the other back up bigs, since the Spurs have a better option to be the dive man on pick and rolls in Splitter and a better interior passer in Diaw. Defensively, lineups including Blair have struggled enormously, but you could make a case for him being a good matchup-up for the physical Randolph. So the reasons to go with Blair would be rebounding and to a much lesser and hypothetical extent, the possibility of better defense. Unfortunately, the best way to beat the Grizzlies seems to be with offense.
The Grizzlies have been out-rebounded both on total rebounds and on offensive rebounds only 15 times this season including the playoffs, so it doesn't seem like trying to beat them at their own game is the best plan and I highly doubt Blair getting limited minutes changes that. Keeping their offensive rebounding in check is important, but the Spurs are already doing that now and trying to force them into high scoring games seems clearly more important. They've won only nine of 25 when the opponent scores more than 95 points in regulation and 51 of 64 when the opponent scores less than 95 points. Simply put, the best way to beat the Grizzlies is to score on them, not to try to out-rebound them or to match their physicality.
That means the Spurs' defense has been good enough to beat the Grizzlies in the past couple of games with Bonner and Diaw getting minutes while the offense struggled dramatically in the second half of game two. Any adjustments made at this point should be geared towards improving the offense without compromising the defense, and I'm not sure playing Blair would accomplish that. That being said, giving him a minute here and there when one of the bigs is in foul trouble could pay off, as his disruptive defense and ability to finish on pick and rolls could jump-start a struggling offense.
As it happens with most playoff series, a couple of adjustments by either coach could render what you just read obsolete. But for now, it seems that having Bonner out there more than Diaw is the best option for the Spurs. Blair could be a good fallback option when everything else fails, but his strengths and weaknesses don't seem to make him a good fit in this series. The completely obvious conclusion here is the Spurs need to score, score, score to beat the Grizzlies and Matt Bonner seems to be the best of the back up bigs at making that happen.
Stats courtesy of NBA.com/Stats and Basketball-Reference