Blocks ≠ Good Defense

[LewisnotMiller]

It's really more about measuring the impact of a defensive player on shots around the basket, in seriousness. Counting stats are crap ways to measure effectiveness since they're entirely contextual.

Points per game is a ham-fisted way to measure scorers. It could rate a volume scorer as being better than an efficient scorer. Steals can confuse gambling with impact. As can blocks.

Blocks, in and of themselves, are fine. But it's the impact of the shotblocker that matters. Not the number of blocks.

As many have already said, that's a much more multi-faceted discussion.

[gavran]

Way too deep analysis, for an issue, that is duuuuuh.

[Ziggie]

You're not factoring in momentum change.

A team's momentum increases significantly after a successful block

Sent from my Pixel 4a (5G) using RealGM mobile app

[JN61]

Uhm. Several teams on that chart are both good blocking team and good defensively team.

Don't make shallow only 1 thing can be true threads. Lesson learned here OP.

[dhsilv2]

I don't understand the point of this graph. To make a graph that actually shows the impact of blocks on defence you have to keep everything else equal, as in here's Miami's D with and without blocks. Which is probably impossible.

Did you mean to say that blocks dont make a good defence all by themselves? Of course they don't, there's a dozen things that matters on D, blocks is just one of them. But if your defence is crap and you add a shotblocker it will still be crap just less so.

The idea is more than great shot blockers generally reduce attempts at the rim all together. Some guys get more blocks because players don't respect their shot blocking. While others they are respected to the point people just don't shoot. So while you could argue almost all blocks are a good defensive play/result. Their isn't that correlation that a team with more blocks is a better defensive team.

[BelgradeNugget]

Don't tell the "Jokic doesn't play good defense" people.

Since blocks are most likely to come near the rim and inviting a player in closer and closer has adverse effects for the defense, it can be seen how defenses that allow lots of blocks can still be bad defenses overall. In the 2022 regular season, a shot within six feet of the basket had a 61.3% chance of going in. Just four more feet out at the distances between six feet and ten feet the percentage lowers all the way to 40.3%. Even when the top ten rim protectors(3) are the ones contesting the shot near the basket, there is only a 50.3% chance the shot will go in.

"When Jokic is on the floor, the Nuggets allow 3.8 percent fewer shots at the rim than average. That ranks in the 93rd percentile among all NBA players, meaning Jokic is elite at preventing shots at the rim despite being unable to jump over a phone book."

https://www.denverstiffs.com/2020/2/10/21131100/stat-of-the-week-nikola-jokic-defensive-impact-nba-rim-protectors-are-overrated

[NO-KG-AI]

Honestly, people try to use blocks as "hE jUsT JuMppz at EvErytHINg" to underrate a defender they don't want to admit is good way more often than they use it to overrate poor defenders.

Usually guys that are not good defenders that block some shots might have an outlier year, or they are guys that block a lot per minute but can't avoid foul trouble or bad plays enough to stay on the floor. Guys who are annual shot blocking leaders are almost always very strong defenders, because they have the ability to stay on the floor to block a lot of shots.

Like someone posted, the top list of shotblockers of all time are great defenders.

[Statlanta]

OP should explain this to Hassan Whiteside, Myles Turner, Mo Bamba and Mitchell Robinson.

[Myth]

Not on their own, no. Look at Mark Eaton.

But then again look at history's leaders in blocks:

Hakeem
Dikembe
Kareem
Duncan
Robinson
Ewing
Mourning
Wallace
Dwight

It means something.

Of course... it's kind of what I was trying to get at with my post. Steals also don't mean you're a good defender overall. Guys like Iverson used to cheat passing lanes and compromise their team defense.

I remember Larry Hughes made some all defensive teams because people were fooled by the Steal stats.

Even James Harden has a good history of steals.

[whatever_]

I love players who just keep their arms high and don't fall for fake shots.

I sometimes fantasize about Marc Gasol's D on Embiid in 2019.

[cupcakesnake]

[hugepatsfan]

The OP's graphic shows that eve the league leader (Memphis) got under 6.5 blocks per 100 defensive possessions. So obviously it can't be all-telling about defense when it's such a miniscule percentage of defensive players.

But actually blocking a shot is the most direct way to contest a shot and stop it from going in. No better contest on a shot than that. And the threat of it can deter shots at the rim and force teams into more difficult ones. But at the same time, if you're chasing weakside blocks you might get an extra 1 or 2 to pump up your numbers but make yourself vulnerable to dump offs or lobs to the man you left.

I'll use Rob Williams from my Celtics as an example since he's always been known for blocks. Prior to this year, the defensive metrics didn't point to such a high overall impact because he was out of control chasing blocks. He was actually a more impactful offensive player than defensive in past seasons. This year, he made huge strides to getting his shot blocking within good, disciplined team defense and he became hugely impactful on that end. His blocks per 100 possessions were at a career low, but his all around defensive impact was at a career high.

Not to say shot blocking is bad. It's a great thing in and of itself. It's only bad when it comes as a result of playing to that statistic vs playing good defense. There's some overlap there between shot blocking and good defense but also some times where they can go against each other too.

[skones]

It's 2008 now.

[mulamutti]

Not on their own, no. Look at Mark Eaton.

But then again look at history's leaders in blocks:

Hakeem
Dikembe
Kareem
Duncan
Robinson
Ewing
Mourning
Wallace
Dwight

It means something.

Team defense has evolved drastically since those days. More simplistic man-man or zone defenses in the past meant that the center had to do a lot of the last line of defense. So the list you have are legitimately great defenders in an era that always required a defensive bail-out guy at the rim as a last line of defense. Nowadays though, there's a lot more switching and team defense, where blocks are less necessary. Especially if it comes at a cost of a slow non-switchable center.

But ur list is not of slow non-switchable centers. I suspect all of them would have been successful in any era. In today's era, i think their block numbers may have been down, but their defensive impact would've still been the same.

Generally I agree with the OP's premise that high number of blocks doesn't automatically mean you're a good defender or good defensive team. e.g. We rarely talk about taking charges as a defensive stat. Taking a charge is more useful than a block. A block may result in the team still maintaining possession, scoring, etc. Going for a block can often put the defender out of position. Taking a charge however, guarantees possession instantly, gets a foul called on the opposing player. So defenses are evaluated a lot differently nowadays, and blocks are not a leading indicator anymore.

[JonFromVA]

As long as there's a GM who will pay for stats, there will be players playing for stats and low number stats should be the easiest to exploit.

But worth pointing out that some defensive teams ask their perimeter players to funnel their man in to the paint where they can be cut off and ideally trapped.

Anyone who's watched Evan Mobley can see he's not just an athletic freak swatting shots, but has a very high defensive iq just like those ATG shot blockers.

[Scalabrine]

It's the most overrated standard statistic in the NBA. 41% of the time is ends up back in the offensive teams possession and often with the defense in scramble mode with the shot blocker out of defensive position.

[benhillboy]

For swarming teams (GS, Heat, Suns, Grizz, Celtics) I’d say attempt blocks at your hearts content, every man on the roster. Richaun Holmes or Cody Zeller should be very cautious about sliding over and leaving their feet at the wrong time. They know their team defensive balance won’t be there.

The cons to a block aren’t remotely comparable to the pros. That corner three block tag team by Draymond and Steph on Dinwiddie essentially ended the game and it was early third quarter I believe. They’re demoralizing and certainly negatively affect shot selection going forward.

Thankfully I think players are contesting threes better than in recent years to avoid the dreaded 3 FTs by turning mid air and landing off to the side of the shooter. Derrick white had a beautiful block on Strus by jumping behind him after fighting through a screen no less (that was recovered and scored for OP lol) We need to see much more of that from perimeter defenders.



Sure if you’re familiar with a player you can easily make a judgment about how intelligent their shot challenges are. But for players I don’t watch often I would never assume high blocks means he’s “chasing,” I’d say he has high awareness on where the ball is and quality of shot contests, especially a guard around .4 or a wing at .7.

I combine raw steals, blocks, and offensive rebounds to get a quick sense of how tough a player is based on their size and minutes. Scottie Pippen Lite is right there in Herb Jones’ stat line.

[anatomicbomb]

looks to me like this graph may better account for variance with two trend lines:
- one for teams that have low blocks
- one for teams that have high blocks

the way i see it, this is a non-trivial difference and pertains to personnel and team defensive strategies. you can have a team with tall, long, athletic players who design their defense to push players into the teeth of it; you can have a team of perimeter players that focus on keeping the opponent out of the paint and trying to deny 3s. this can even change, game-to-game, depending on who is available and who the opponent is.

while i find the premise interesting, i feel like the statistical basis leaves a lot of room for alternative interpretations, and the argument "blocks not= good defense" is kind of a given - blocks can help defense, but may cause other problems (chasing them, uncontrolled deflections close to basket), and are neither necessary nor sufficient for good defense. however, this is not to say that good defenders don't get blocks, or that good defenses can't get lots of blocks. yet, i have not heard anyone - especially a coach or player - claim that getting blocks means they are playing good defense, so i am not entirely sure what the argument is meant to rebut.

that said, always nice to see a post that is thoughtful, uses clear examples, and doesn't attack anyone.

[Johnny Bball]

Steals> blocks

[bigbreakfast]

You're not factoring in momentum change.

A team's momentum increases significantly after a successful block

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some good stuff here. marcus camby comes to mind. the dwight effect stuff was some great stuff and kinda kicked off the analytic era.

I think the momentum thing is... anecdotal at best. would love to see if anyone has actual data on that versus just someone's opinion from watching a game. same thing with "being hot"