Rim Protection Data Dump
Top 2? Related to the piece I had up on ClipperBlog yesterday (thanks to Andrew Han for running it), I recalculated "Isolated Rim Protection" values up through games of Monday the 20th. Based on a suggestion from Rob, I ran the whole league, not just big men, though obviously "rim protection" is a far less important stat for wings and guards than for bigs. But, looking at the whole league (well, players who had played at least 20 games and at least 10 minutes per game) reveals the contribution each "position" on the floor tends to have in protecting the paint:
| Player | GP | MPG | OFG/gm | Cont/gm | OFG% | PS/GM | SV/36 | Cont/36 |
|---|---|---|---|---|---|---|---|---|
| All Players | 35.2 | 25.4 | 1.7 | 3.3 | 51.3% | 1.54 | 2.19 | 4.62 |
| Point Guards | 33.9 | 25.9 | 0.7 | 1.3 | 55.1% | 0.52 | 0.73 | 1.83 |
| Shooting Guards | 36.0 | 26.8 | 1.0 | 1.8 | 55.3% | 0.70 | 0.94 | 2.39 |
| Small Forwards | 35.3 | 25.8 | 1.3 | 2.5 | 52.7% | 1.10 | 1.54 | 3.45 |
| Power Forwards | 35.3 | 23.5 | 2.4 | 4.7 | 51.2% | 2.23 | 3.42 | 7.20 |
| Centers | 35.7 | 25.0 | 3.2 | 6.6 | 48.2% | 3.54 | 5.09 | 9.49 |
| Guards | 34.9 | 26.3 | 0.9 | 1.5 | 55.2% | 0.61 | 0.83 | 2.11 |
| Forwards | 35.3 | 24.5 | 1.9 | 3.7 | 51.7% | 1.73 | 2.53 | 5.43 |
| Wings | 35.6 | 26.3 | 1.1 | 2.1 | 53.8% | 0.90 | 1.23 | 2.90 |
| Bigs | 35.4 | 24.1 | 2.7 | 5.5 | 49.8% | 2.76 | 4.12 | 8.16 |
OFG/GM is makes per game by opponents when the player is contesting the shot; Cont/gm is number of contests at the rim per game; PS/GM is "raw" points saved per game; SV/36 is "raw" saved per 36 minutes; Cont/36 is number of contests at the rim per 36 minutes.
These are "raw" numbers. That is to say, the number of points "prevented" by the player contesting a shot at the rim relative to an uncontested shot. The numbers I'm going to use from here on out are relative to position or category average. When evaluating players it doesn't necessarily matter how much better a defender the guy would be than the chair from Yi Jianlian's pre-draft workouts. Rather, how good is he relative to the next guy who could take his job. This scaling to average lets us say that despite "saving" almost a full bucket per game (those two points per game wou ld make a very sizable difference in a team's expected W-L), Carlos Boozer is not in fact a good rim defender.
But looking at the "raw" numbers shows just how much of the burden of rim protection falls on 4's and 5's. Just under 2/3rds of the "contests" in this sample were accomplished by bigs. And this is not a result of their opposite numbers taking the vast majority of close shots; though shots within 5 feet of the rim skew towards the bigger players, not nearly to the degree which the number of defensive contests at the rim do. To put it another way, Draymond Green ranks highest in contests/36 of any player who doesn't spend substantial time at the 4 or 5, and he ranks 104th in the league, by comparison 11 of the current top 25 in attempts per game under 5 feet are non-bigs.
So the burden of rim protection unsurprisingly falls mostly on centers and to a slightly lesser extant power forwards. That said, there are some players who do provide hidden value from other positions. For example, despite his shot blocks being way down this year from his first several years in the league, Phoenix's Eric Bledsoe is one of only 2 guards (alongside Jeremy Lin) in the league who save more than 1 point per game more than the average guard. Other smaller players who provide surprising value in this area include Victor Oladipo, Reggie Jackson and Kirk Hinrich.
Wings providing good value in this area include:
Wings who are particularly remiss in this area are two somewhat surprising players, Corey Brewer and Trevor Ariza. Given their athleticism and length, you might expect these two to be at worst average, but my guess is their penchant for gambling and leaking out on the break takes them away from the rim too much to actively contest many shots. In fact among non-big men Ariza and Brewer are the only two who provide a full point or more in negative value - that is replacing them with a league average 3, and the team's rim protection would be a full point better. As a reminder, this metric is isolated rim protection, so I'm not making any claims about either players overall defense (though especially about Brewer, I have my doubts.)
Regardless, as only 6 non-bigs provide more than a point per game of value either way (Bledsoe, Lin, Green and Pierce in the positive and Brewer and Ariza in the negative), the real difference in team rim protection is seen in big men. Across the 118 big men in the sample, the spread of per game value ranges between 3.81/gm saved over average (Roy Hibbert of course) to -2.24/gm under average (Thaddeus Young). Rather than post long lists like I've done in the past, I've posted a spreadsheet of the values, including breakdowns by position and category (guard, forward, wing, big).
These are "raw" numbers. That is to say, the number of points "prevented" by the player contesting a shot at the rim relative to an uncontested shot. The numbers I'm going to use from here on out are relative to position or category average. When evaluating players it doesn't necessarily matter how much better a defender the guy would be than the chair from Yi Jianlian's pre-draft workouts. Rather, how good is he relative to the next guy who could take his job. This scaling to average lets us say that despite "saving" almost a full bucket per game (those two points per game wou ld make a very sizable difference in a team's expected W-L), Carlos Boozer is not in fact a good rim defender.
But looking at the "raw" numbers shows just how much of the burden of rim protection falls on 4's and 5's. Just under 2/3rds of the "contests" in this sample were accomplished by bigs. And this is not a result of their opposite numbers taking the vast majority of close shots; though shots within 5 feet of the rim skew towards the bigger players, not nearly to the degree which the number of defensive contests at the rim do. To put it another way, Draymond Green ranks highest in contests/36 of any player who doesn't spend substantial time at the 4 or 5, and he ranks 104th in the league, by comparison 11 of the current top 25 in attempts per game under 5 feet are non-bigs.
So the burden of rim protection unsurprisingly falls mostly on centers and to a slightly lesser extant power forwards. That said, there are some players who do provide hidden value from other positions. For example, despite his shot blocks being way down this year from his first several years in the league, Phoenix's Eric Bledsoe is one of only 2 guards (alongside Jeremy Lin) in the league who save more than 1 point per game more than the average guard. Other smaller players who provide surprising value in this area include Victor Oladipo, Reggie Jackson and Kirk Hinrich.
Wings providing good value in this area include:
- Paul Pierce
- Green (really a stunningly effective player for Golden State Warriors despite his lousy shooting stats, and far outperforming the prodigal Harrison Barnes in this area)
- Giannis Antetokounmpo, who if Larry Drew would just commit to playing 35 minutes per might challenge Nicolas Batum as my favorite current player in the league
- Omri Casspi, Shawn Marion and Michael Kidd-Gilchrist, all of whom spend some time as small ball 4s.
Wings who are particularly remiss in this area are two somewhat surprising players, Corey Brewer and Trevor Ariza. Given their athleticism and length, you might expect these two to be at worst average, but my guess is their penchant for gambling and leaking out on the break takes them away from the rim too much to actively contest many shots. In fact among non-big men Ariza and Brewer are the only two who provide a full point or more in negative value - that is replacing them with a league average 3, and the team's rim protection would be a full point better. As a reminder, this metric is isolated rim protection, so I'm not making any claims about either players overall defense (though especially about Brewer, I have my doubts.)
Regardless, as only 6 non-bigs provide more than a point per game of value either way (Bledsoe, Lin, Green and Pierce in the positive and Brewer and Ariza in the negative), the real difference in team rim protection is seen in big men. Across the 118 big men in the sample, the spread of per game value ranges between 3.81/gm saved over average (Roy Hibbert of course) to -2.24/gm under average (Thaddeus Young). Rather than post long lists like I've done in the past, I've posted a spreadsheet of the values, including breakdowns by position and category (guard, forward, wing, big).
Another point of interest is to look at some season split comparisons to see if players are performing better or worse since the start of the campaign. One of the more frustrating things about NBA.com's player tracking data is that there is as yet no way to filter by date, so I can only do apples to apples comparisons for the 60 or so players who I looked at both in early December and today. One such comparison looks at DeAndre Jordan, whose improvement is the subject of the ClipperBlog piece, but there are some others worth looking at. Robin Lopez is a player was a surprise to find at the top of the earliest versions of this analysis, how much of Portland's recent (well, long standing really) defensive swoon resulted from his deteriorating play in terms of protecting the rim? The answer is, a fair bit. Lopez is still well into the positives, but is preventing around 3/4 of a point per game less relative to average than he was over the first quarter of the season. Happy to look at other players if people would like, drop a note in comments or on twitter.
In any event, the spreadsheet can be found here, hope to update in about quarter-season increments from here on out.
In any event, the spreadsheet can be found here, hope to update in about quarter-season increments from here on out.
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