Bulls Hit: off day 2/26

Taj at the 5, I hardly knew ye…

1- I was wondering how often Taj Gibson played at the five this season. That is, how often was Gibson the primary rim protector on the floor? How effective was this defensively and how effective was it offensively? In almost 60 games I remember Fred Hoiberg using it occasionally, but then again, I’m usually drinking when I watch so I can’t be sure. It would certainly make sense, considering the direction the NBA is taking. According to Basketball Reference’s play-by-play positional estimates, Taj played at center for only 2% of his total playing time this season. Specifically, Taj Gibson has (allegedly) played only 30 of his 1544 total minutes this season minutes at center.

This doesn’t feel right; 30 minutes is quite a small amount and it’s almost negligible when played over 59 games so far this season. So I decided to look into it a little: according to nba.com’s 2-man lineup trackers, the combination of Mirotic and Gibson have logged 216 minutes over 31 games this season. I also suspected, however, that these two-man lineups weren’t positionally exclusive (as in, other power forwards or a center also could have been playing during some of these 216 minutes — remember Hoiberg’s Mirotic at the three experiment? Kill me). To combat this I plugged the Mirotic / Gibson lineup MINUS Portis, Felicio, and Lopez into nbawowy and it showed that 181 total minutes were played with Mirotic and Gibson as the only big men on the floor.

So, of Taj’s 1502 total minutes played for the Bulls this year (per Basketball Reference), 181 of them were played with Mirotic as his frontcourt partner, which measures out to around 14% of his total playing time this season. According to the numbers from nbawowy, that duo posted an ORTG of 112.8 and a DRTG of 103.6, producing a net rating of 9.2. For 151 of those minutes Jimmy Butler was also on the floor with an insane 65.9 TS% and 1.33 points per possession on 36.2% usage. Gibson also seemed to dominate offensively posting a 61.9 TS% with 1.24 points per possession he used. Nikola Mirotic, on the other hand, was fucking terrible in this lineup: 38.4 TS% and .86 points per possession.

In essence, it was an interesting thing to look at, but the sample size was just too small to reveal anything meaningful in my opinion. Sorry for wasting your time.

RIP this lineup.

2. On the other hand, the Taj Gibson / Robin Lopez frontcourt has averaged a 103.4 ORTG and 105.0 DRTG with a -1.6 net rating in 1169 total minutes this season, according to nba.com’s 2-man lineup statistics. In contrast, the Nikola Mirotic / Christiano Felicio pairing has a positive net rating of 2.9 in 462 total minutes this season. I’ve documented how disastrous a Bobby Portis / Nikola Mirotic duo is and could be, and the Portis / Felicio combo has a -3.5 net rating.

The Bulls were in a unique position when it came to their power forward rotation this season: both Mirotic and Gibson are lower-tier starting caliber players. That is, both of them are good enough to start, but both of them are also better than most second-string power forwards in the league. Ironically, the team that acquired Gibson faced a similar conundrum before the trade. Billy Donovan and the Thunder opted to start rookie Domantas Sabonis at power forward as opposed to veteran scorer Enes Kanter, who they brought off the bench. I can only speculate as to Donovan’s reasons for doing this, but my guess is that since Sabonis is a better three-point shooter (31.5% on 2.2 shots per game, which is bad, but Kanter has never attempted more than .5 a game), his spacing on offense is enough to compensate for his defensive shortcomings. The Thunder miss Kanter’s scoring and elite rebounding on their first unit, but instead he’s taken to leading the second unit and roasting most opposing second-unit big men in the process. (I’m aware of Kanter’s defensive pitfalls, but is he really worse than a rookie? Come on.)

The Bulls were in a similar position with Gibson and Mirotic. I can’t know Hoiberg’s reasoning (believe me, I’ve tried), but I can speculate that he trusts Gibson more and that Gibson’s defensive ability and rebounding trumped Mirotic’s floor spacing. Fair enough. But now that Gibson’s gone, you’d think that Mirotic would become the starter by default. Wrong. Instead, he’s opting to start Bobby Portis in his place.

In my view, there’s no justifiable reason as to why Portis should start over Mirotic. Here’s something funny about this: Portis is playing fewer minutes than Mirotic but he’s still the one starting. In the two games since the trade deadline, Portis has played an average of 17 minutes and Mirotic has played 32.5. In those two games Portis has logged a -7 +/- and Mirotic has been at +19.5. I don’t see the reasoning in starting Portis, only to have him get skewered by starting-caliber power forwards, and then play him bench minutes. He’s a bench player playing bench player minutes but he’s still starting. What the fuck? We’ll see how he plays against the physical Denver frontcourt tomorrow.

3. With Gibson on the floor (1287 minutes), 24.8% of offensive possessions have ended with Jimmy Butler. In these possessions, he’s shot 46.6% from the field with a 58.4 TS%, and has scored 1.16 points per possession with a 2.4 net rating. Without Gibson on the floor (664 minutes), Butler’s usage rate balloons to 32.1% while his FG% and TS% drop to 41.1 and 54.8 respectively. However, he still scores 1.15 points per possession with an 8.2 net rating. The team’s DRTG (points allowed per 100 possessions) is virtually identical with Gibson on and off the floor while Jimmy Butler is still on the floor. I don’t know what any of this means. Jimmy Butler is good no matter what.

4. According to nba.com’s player on/off numbers, the Bulls’ DRTG (points allowed per 100 possessions) with Gibson on the floor is 104.5 and 106.6 when he’s not on the floor. The Bulls’ ORTG (points scored per 100 possessions) is 104.4 with Gibson on the floor and 105.3 without him. However, Gibson’s overall net rating (ORTG minus DRTG) is only -0.1 when he’s on the floor compared to a -1.3 rating when he’s off. So the Bulls were better with him on the floor. Makes sense.

5. Only two Bulls players have positive net ratings according to nba.com’s on/off metrics: Jimmy Butler (3.7), Mirotic (2.7), Jerian Grant (1.3) and Paul Zipser (0.8). Grant and Zipser haven’t logged enough playing time to produce an accurate measurement of their play and, as mentioned above, Mirotic might be a little better than most bench guys but worse than most starters. Jimmy Butler is very good. The Bulls shouldn’t trade him.