Numbers for thought: Is Greg Monroe an underrated defender?

Numbers for thought is a series that selects certain pieces of statistics before each game (or let's say every now and then to make this a more attainable goal) that may or may not be meaningful (you know, small sample size, outliers or whatever) but nonetheless provide entertainment value (or so I hope).

It's official: Greg Monroe is going to meet with the Celtics. Would Monroe spark the "fireworks" that we have been waiting for more than a year now? Probably not. Is he the dream "rim protector" the Celtics have been salivating over for years now? Definitely not. But let's be honest here: Greg Monroe is one of the most realistic free agent targets for the Celtics, he's a great offensive weapon and a still young player with great upside. This much you've probably already known, so I'm here to convince you of something else: He is actually a decent defender despite the label attached to him since he stepped foot in the NBA. Let's look at some numbers courtesy of nba.com, shall we?


The usual but important disclaimer before I dig in: Basketball is a team sport, and a comprehensive statistical tool that measures defensive success has not been developed yet. Therefore all defensive analyses suffer from an omitted variable bias. If you are playing with horrible defensive players your individual stats will also suffer, and vice versa. Any number that is not supported by the "eye test" can therefore be misleading. That being said, here is a Stan van Gundy quote on Greg Monroe:

"I think Greg's actually pretty good defensively," Van Gundy said. "I've thought that all year.

"He's a very good low post defender, in my opinion. And he's a smart defender. He doesn't make a lot of mistakes."

Source: The Detroit News

Wait, what? Stan "no bullshit" van Gundy thinks Monroe is a good defender? Now it's time to look at the numbers:

One really good measure of a player's defense is the comparison of Defended Field Goal percentage (DFG%) and FG%, which measures how the opponent against the player in question shoots vs. how he does in general. Monroe's assignments shot 60% from less than 6 ft. on average against other players last year. When Monroe defended them, that number was 60.1%. Yep, that's a 0.1 percentage point difference, which is as negligible as one can get statistically. Monroe fared a bit worse when the opponents were farther away from the basket (0.9 percentage points worse from less than 10 ft., 0.5 worse from less than 15 ft.), but in general he in no way offered those players an open house.

Another useful piece of statistics is Opponent Points in the Paint (Opp PITP), which I think is self explanatory. Monroe allowed 33.6 Opp PITP per 36 minutes, which is not a great number as he ranks really low among fellow centers in the league. However, his numbers were still better than or very close to Celtics players like Brandon Bass and Tyler Zeller, or other potential green targets such as Nikola Pekovic, Robin Lopez and Omer Asik. Again, this stat is not necessarily meaningful because paint defense is not solely the center's responsibility -and it actually paints Anthony Davis as one of the worst defenders in the league which is obviously not true- but what it shows is that the Celtics could or would do worse without Monroe than with him, and they ranked 26th last year in that category so any help would be welcomed.

Greg can also intimidatingly eat his jersey if all else fails.

If you're not impressed with the numbers above, here's something that will cheer you up. Opponent 2nd Chance Points (Opp 2nd Pts) is a more accurate indicator of a big man's effort in the paint because if an opponent gets the offensive rebound, their first option is usually to score the ball right away, and in most cases only the big men are there to deter that shot. Greg Monroe is actually one of the best in that category as he allowed only 9.1 Opp 2nd Pts per 36 minutes. That either means he doesn't let other players get the offensive rebound that often so they have less chances to score, or he actually recovers pretty well when they give away a rebound. Either way, he would be a very good addition to a Celtics roster that ranked 18th last year and got crushed in the Playoffs by Tristan Thompson alone.

I've talked about how these statistics can be biased towards a player since his team can be terrible defensively, or certain lineups can make him look worse than he is. One way to look at that is to compare On Court and Off Court Defensive Ratings. When Monroe is on the court, the Pistons allowed 103.7 points per 100 possessions. Not good, right? But when Monroe was on the bench, that number was actually higher: 104.7. When Andre Drummond, Monroe's frontcourt partner, was on the court, the Pistons had a 105.5 DefRtg compared to 101.9 when he was off. Monroe actually made his team allow less points as he was out there playing. Again, this metric inherently favors players who play against second units, but at least it shows that Monroe didn't create a drastic effect on defense. Hey, and if you don't believe those numbers, ask Zach Lowe:

Monroe is playing the best all-around ball of his career and deserves stronger All-Star consideration than he appears to have received. He has outplayed Drummond for the balance of the season, and he’s working harder than ever on defense — at both big-man positions.
Source: Grantland