The value of a block on defense?

[TwentyOne920]

One of the stats people like to bring up when determining the defensive impact of players, especially big men, is the shot block. One easy way to make All-Defensive teams is to block a lot of shots.

But not all blocks are created equal - blocking a jump shot is not the same as blocking a layup. And sometimes, going for a block may not prevent opponents from scoring points as much as they would indicate - if a player gets blocked but a teammate recovers the ball, it's effectively the same as an offensive rebound. Only blocks that result in a change of possession are as efficient as forcing a turnover or a missed shot.

So, how much correlation is there between volume of blocks and overall defense? Keep in mind Serge Ibaka leads the league in blocks but his team is only 11th in defensive rating, and the same was true of the Nuggets when Marcus Camby won Defensive Player of the Year.

[An Unbiased Fan]

I really don't value block stats. To me, it's like counting dunks per game on offense.

That's not to say a good controlled block isn't a great defensive play, I just think good defense is good defense, no matter how it's done.

[MacGill]

To me, blocking shots is only part of the equation and is moreso the flashy part of the defense which casual fans enjoy. Preventing 2 points is always a good thing and like AUF points out, controlling the block even better. I think a good comparison would be Ibaka vs KG between the differences. KG was never known as a great shot blocker but you can see the amount of court he can impact defensively. Serge to date doesn't impact the amount of court KG does but does a better job being an overall shot blocker. In the end, you'll be much better off with the overall impact minus higher bpg but you really have to watch how KG impacts the court to get the full picture. So while being a good shot blocker is better than not being able too, you can have amuch greater impact on the game with the shot blocks at a minimum.

[nhh90]

http://www.82games.com/comm16.htm

[SWedd523]

On a team basis, the Bobcats were 8th in blocked shots last year, yet had the worst defense in the league. That should tell you all you need to know.

On an individual basis, I think shot blocking is overrated. It's just one aspect of a complete defensive impact. A guy like Tyrus Thomas is a great shot blocker, but a poor overall defender for a big man because he's lacking in many other areas.

[Bucksmaniac]

I think this year's Milwaukee Bucks team will be an interesting test case in the value of a block. We were not a very good defensive team and we were near the middle of the league in blocked shots. This year, I think we may have arguably one of the best pure shot-blocking teams of all time, likely to lead the league in the stat if the right frontcourt players receive minutes and are active. Will this guarantee we are one of the best defensive teams? Not sure, but we have good position/individual defenders as well in Mbah a Moute, Ilyasova, and Marquis Daniels. None of those three are very good shotblockers, but for shotblockers we have Dalembert, Udoh and Sanders who were all among the top 15 in blocked shots last year, not to mention John Henson, who looks to be a very good shotblocker if he progresses and sees minutes. 2nd year player Tobias Harris had 4 blocks the other night against Detroit, so it's possible he progresses as a shotblocker as well. We shall see, unfortunately we have a poor defensive frontcourt, of course that could also serve to inflate the team's block totals as well if the opposing guards fly by our guards toward the hoop all the time.

[Doctor MJ]

Blocks really don't necessarily mean much at all. Or rather, any block you see is a play to watch and re-watch to see how the player is going about doing it, as that tells you a ton about the player's defense, but it is absolutely possible to do more harm than good by chasing blocks. Case in point: Jevale McGee.

This is a place where I love +/- stats. If you see a guy blocking a lot of shots and doing really well be defensive RAPM, it's basically a given that the man's blocked shots are doing some serious good. And while blocks on their own without more evidence can be a good or bad thing, +/- stats on their own aren't really enough to give me confidence in assessing the player. Used in conjunction though, it's like chocolate & peanut butter.

[jman3134]

^ Excellent points all around. Only thing I would add is the psychological impact of a block on players attacking the basket. There must be some statistical evidence to support this effect.

[Doctor MJ]

^ Excellent points all around. Only thing I would add is the psychological impact of a block on players attacking the basket. There must be some statistical evidence to support this effect.

Well you're hitting upon another very important point here that makes non-+/- analysis so dang hard:

The value of the block isn't the block so much as the shot alteration. No matter how you look at it, a successful steal is going to be more valuable on average than a successful block. However, shooters put tons of effort into avoiding blocked shots in a way they simply don't have to with steals. And by "tons of effort" I mean, "taking FAR worse shots than they'd take in an open gym".

Some of this is psychological, but much of it is simply correct. Defenders force you to choose between this or an actual block.

[Dr Pepper]

So, how much correlation is there between volume of blocks and overall defense? Keep in mind Serge Ibaka leads the league in blocks but his team is only 11th in defensive rating, and the same was true of the Nuggets when Marcus Camby won Defensive Player of the Year.

I don't know about the correlation between volume of blocks and overall defense, but like you basically said it probably comes down to this phrase: It Depends. Like you mentioned, not all shotblocking is equal.

As [Huizinga] explained, through a series of charts, Tim Duncan has had the best season in history when it came down to value/block with 1.12, meaning he saved 1.12 points with every block and Dwight Howard ended up with the worst season in terms of value/block with with .53 (both came during the 2008 season).

http://espn.go.com/blog/truehoop/post/_ ... ocked-shot

There was a 2010 study called "The Value of a Blocked Shot in the NBA: From Dwight Howard to Tim Duncan" by John Huizinga and Sandy Weil featured at the MIT Sloan Sports Conference that analyzed the value of a blocked shot, but their NBAplaybook.com link is down and that had a lot more stats than the above link which is more of an excerpt.

In that study, which spanned for 7 seasons and included all NBA players, it revealed that blocking jumpshots is significanly less valuable than blocking a layup at the rim, and the study focused on what happened to the ball after the block (was it a goaltend? - a fourth of Dwight's blocks were goaltends, did the team get the possession after the shotblock?, did the shotblocker block like Bill Russell and throw an outlet easy fast break opportunity?, etc) .

Tim Duncan is a master at protecting the rim, and doesn't compromise his defense by going for jumpshots and goaltends. Unlike Dwight Howard whose blocks were 1/4 of the time goaltends, Duncan had zero for that timespan. Furthermore, Duncan's got an uncanny ability to block the ball to his team so his team has possession.



At the two-minute mark, check out that clip from the recent WCF. Even an old Tim Duncan is able to make a crazy block protecting the rim from Westbrook's layup, and while falling out of bounds Duncan is able to pass/deflect the ball into his teammate Boris Diaw's hands who was a midseason trade acquisition. Sure you don't want Duncan to fall down but that's just more of an example of Duncan's uncanny shotblocking talent

The study had numbers for Camby too and his shotblocking (IIRC) turned out to be well deserved of praise, but of course there's more to defense than that and Duncan should've had a DPOY at some point in his career.

When it comes to bigs, you want both a great defender that can roam and an elite shotblocker (and great offense)...then you got yourselves a Duncan dynasty in the making.

[TwentyOne920]

Funny, I had that EXACT article in mind when writing the OP. Still a nice insight, and I think that's what separates the good big defenders from the great - the great defenders contest with footwork unless it's absolutely clear that contesting the shot in the air is the best option left.

[Americafkya]

While I think that blocks are overrated, it really can never be a bad thing. Obviously blocking a layup is worth far more than blocking jumpshot, but that doesn't mean that blocking a jumper is useless. What I do think people often overlook is how few blocked shots there really are, and how going for a block every time can really hurt a defense. Challenging every shot should be the goal. Obviously tim Duncan and KG being good examples of elite defensive players that could block shots, alter them, anchor a D, and still stay out of foul trouble.

Still a block is demoralizing for a player, and often serves as a catalyst for the offense in transition. Even watching from TV its hard not to get energized when you the announcer " BLOCKED BY CHANDLER!!" " REJECTED BY IBAKA"!! SENT BACK BY HOWARD!!!".

A block in a vacuum is hugely valuable. Say a good finisher goes in for a layup. Say they finish that layup 80% of the time and its worth two points. That means that layup is worth 1.6 points in our vacuum example. A block totally wipes the points away. Say an offensive is really efficient and scores 110 points per 100 possessions , thats 1.1 per. A block will cost that team 1.1 points.

But nothing takes place in a vacuum so I guess we can throw that out the window lol. Just because a player gets one key block doesn't mean they have " helped" the team. There is a good chance that they don't play good defense and leave their feet too much. Remember when Amare blocked what would have been a game winning layup by Lebron last year in a Knicks/Heat game? Huge block....but amare isn't a good defender. In fact his propensity to go for every block makes him a bad defender. We as humans tend to look at just the event and make assumptions because thats basically the way the natural world works. So we see a player hit a buzzer beater and label him the hero , but what people don't realize is that player went 6/20 had 5 personal fouls and left his feet too many times going for blocks allowing the offense to eat up the paint.

So after all of this rambling I come to the conclusion that I have no idea what im talking about. I don't think blocks are so much the important thing. I think what is more important is to have a defensive anchor that has the capability of getting blocked shots, but only when they know they should go for them. Challenging shots and layups is far more important.

[Doctor MJ]

While I think that blocks are overrated, it really can never be a bad thing. Obviously blocking a layup is worth far more than blocking jumpshot, but that doesn't mean that blocking a jumper is useless. What I do think people often overlook is how few blocked shots there really are, and how going for a block every time can really hurt a defense. Challenging every shot should be the goal. Obviously tim Duncan and KG being good examples of elite defensive players that could block shots, alter them, anchor a D, and still stay out of foul trouble.

Still a block is demoralizing for a player, and often serves as a catalyst for the offense in transition. Even watching from TV its hard not to get energized when you the announcer " BLOCKED BY CHANDLER!!" " REJECTED BY IBAKA"!! SENT BACK BY HOWARD!!!".

A block in a vacuum is hugely valuable. Say a good finisher goes in for a layup. Say they finish that layup 80% of the time and its worth two points. That means that layup is worth 1.6 points in our vacuum example. A block totally wipes the points away. Say an offensive is really efficient and scores 110 points per 100 possessions , thats 1.1 per. A block will cost that team 1.1 points.

But nothing takes place in a vacuum so I guess we can throw that out the window lol. Just because a player gets one key block doesn't mean they have " helped" the team. There is a good chance that they don't play good defense and leave their feet too much. Remember when Amare blocked what would have been a game winning layup by Lebron last year in a Knicks/Heat game? Huge block....but amare isn't a good defender. In fact his propensity to go for every block makes him a bad defender. We as humans tend to look at just the event and make assumptions because thats basically the way the natural world works. So we see a player hit a buzzer beater and label him the hero , but what people don't realize is that player went 6/20 had 5 personal fouls and left his feet too many times going for blocks allowing the offense to eat up the paint.

So after all of this rambling I come to the conclusion that I have no idea what im talking about. I don't think blocks are so much the important thing. I think what is more important is to have a defensive anchor that has the capability of getting blocked shots, but only when they know they should go for them. Challenging shots and layups is far more important.

Sounds you have a plenty good idea what you're talking about, it's just hard to communicate intricacies elegantly.

There is no defender more valuable than a guy who can alter shots prolifically without getting burned, but committing fully to altering shots will get you burned.

[turk3d]

Depends on what happens after the block:

1) Does the ball change possession?

2) Does the team that gets blocked get the ball back and do they score on the next possession?

3) Does the team that gets blocked get the ball back and and get stopped again?

[Americafkya]

Depends on what happens after the block:

1) Does the ball change possession?

2) Does the team that gets blocked get the ball back and do they score on the next possession?

3) Does the team that gets blocked get the ball back and and get stopped again?

I dont think that this thought process if fair to the defender. So much that happens after the block is out of his hands. Where are his teammates standing? Where are the opponents standing? How hard was the offensive player going to the rim? Did he get a full hand on it? etc etc etc. A player can get a great block, but if he is unlucky and one of the opposing team's players ends up with the ball for a layup...does that mean he did a bad thing by blocking the shot? No, certainly not. What if the offensive player is going baseline? does that mean you shouldn't block it because it will probably go out of bounds? No its important to stop the ball from going in the hoop.

Are there certain times when a talented player is able to see a step ahead and block it so that it ends up in his teammates hand? ?Yes, Im sure that happens, but very rarely. I think it is important for us to look at the event , in this cases the blocked shot, just focusing on what the defender can realistically control. Which would be blocking without fouling, and not leaving your feet for a bad block attempt, or falling for fakes etc. There are some times that I watch a defender go for a block and just think " wow that was idiotic" There are just some shots you cannot block. Like a skilled dunker going in for a dunk straight away, and the defender coming from the side having to reach across the body to get to the ball. 99% of the time you are fouling there, I'd say 50% of time you are giving up an and 1, and 1% of the time are you getting the block. So basically by going for the block you are actually giving the other team points in the long run.

Take a player like Tyson Chandler for instance. He has an uncanny ability to swat the ball out and keep it alive. Is it bad that he sometimes swats the ball out and the opposing team ends up with the possession? No, because not going for the swat out would lead to the opposing team getting the rebound 100% of the time, going for the swat out to keep it alive gives his team a very good chance at keeping the possession alive. It shouldn't reflect poorly on him if things outside of his control ( the position of the players on the court) ends up producing a negative result.