Wednesday, August 11, 2010

The Anatomy of a Block: By Shot Type (Part 3)

In case you missed it, check out Parts 1 and 2 in this series on "The Anatomy of a Block": Introduction and By Shot Location.

In this post, I'll take a look at the value of a blocked shot based on the shot type. The first thing to figure out is what type of shot types are recorded in the PbP dataset provided by Basketball Geek (I really can't stress enough how thankful I am that Ryan J. Parker provided this data). I grouped every shot with a recorded shot type from the 2007-2010 seasons and found the number of shots taken as well as the total points scored in order to figure out points per shot by shot type (there are 63 different types of shots in the PbP data). Let's look at several lists of shot types: 1) Most shots taken, 2) Highest points per shot, and 3) Lowest points per shot.

Big top 15 tables there. I've added effective field goal percentage (eFG%) which is just field goal percentage taking 3-pointers into account (however, I will be talking in terms of PPS rather than eFG% in order to remain consistent throughout this study). Most shots are categorized generically, for example, jump or layup or dunk instead of the more specific like jump bank hook or turnaround finger roll or putback reverse dunk. It's definitely interesting to see how many driving layups and reverse layups are distinguished from the generic layup.

In the second table, clearly dunks and layups of the eclectic variety return the most points per shot, with several thousand slam dunks averaging 1.956 points per shot (note here that an alley oop dunk averaged 1.814 PPS through four seasons of data, so next time your team messes up an alley oop dunk, it's alright to throw a tantrum). In the third table, generic jump shots (0.692 PPS) and hook shots (0.907 PPS) are the least efficient shots by this measure, but it's also important to note that the generic layup (0.914 PPS) is a close third. In addition to the 118,804 generic layups recorded, there are more than 69,000 other categorized layups as well, all of them being high value shots within 1.3-1.7 PPS.

Now let's take a look at which shot types result in or avoid being blocked the most: 1) Most shots blocked, 2) Highest % of shots blocked, and 3) Lowest % of shots blocked:

The second and third tables are the truly interesting ones here. 19.73% of all generic layups were blocked in 2007-2010, while 13.65% of all driving jump shots were blocked. Several other types of layups were also blocked more than 5% of the time. For these driving and reverse layups as well as the generic dunk, having efficient point values ranging from 1.345 PPS to 1.749 PPS are more important numbers than the block percentages. For instance, even though a guard driving in only to get blocked can be infuriating, keep in mind that a successful driving layup attempt goes in 73% of the time even if it is blocked 7.57% of the time (by successful, I mean successfully penetrating the defense up until the shot). Check out the end of this post to see the entire list of shot types.

Now let's go back to the players. Similar to the blocks by shot location post from yesterday, I took the points per shot for each shot type and multiplied that by the number of blocks of a particular shot type for each player. Summing it up, I found the total number of points saved by shot type and the points saved per block. Let's take a look at the top 25 shot-blockers in terms of total blocks since the 2007 season and see how they fared in points saved per block:

The values for points saved per block by shot type here actually vary more than the values by shot location I looked at yesterday. Here, Josh Smith (1.027 PPS) and Erick Dampier (1.022 PPS) saved the most points per blocked shot based on shot type in this top 25 list, while Andris Biedrins (0.860 PPS) and Brendan Haywood (0.875 PPS) saved the least, just like the table by shot location. Moving along, let's look at both the top 10 and bottom 10 shot-blockers in points saved per blocked shot based on the shot type (minimum of 200 blocks since 2007):

Chris Bosh (1.119 PPS), Joel Przybilla (1.112 PPS), and Chris Anderson (1.090 PPS) come out on top again, all three being among the top 10 in value by shot location. Andris Biedrins (0.860 PPS) and Andray Blatche (0.865 PPS) were also in the bottom 10 in value by shot location, but it's guys like Biedrins, Haywood (0.875 PPS), Roy Hibbert (0.876 PPS), and Shaq (0.879 PPS) who are noteworthy. The four appear in the bottom 10 of the other table, indicating that they are not as valuable to their teams for their shot-blocking abilities as we may have thought in the past by both measures.

Finally, and mostly just for fun, let's take a look at the players who tallied the most blocks since 2007 for different shot types:

Whew, hope you're still with me. Marcus Camby blocked the most generic layups, reverse layups, and running jump shots since 2007, second most for driving layups. To me, this says that Camby is very good at knowing when and where the shooter is just about to release his shot, whether it's off the dribble, a reverse, or a running jumper. Meanwhile, Dwight Howard blocked the most generic jump shots and hook shots since 2007. This tells me that Howard benefits greatly from a huge vertical leap in order to swat away these type of shots. (Diversion: A quick look online tells me that Howard has a 40-inch vertical jump. Current players with higher verticals include LeBron James, Shannon Brown, Vince Carter, Nate Robinson, and Gerald Green. Retired players with higher verticals include Spud Webb, Michael Jordan, Dee Brown, Shawn Kemp, and Dominique Wilkins. Definitely no surprises here.). Finally, Andre Iguodala, Tayshaun Prince, and Kevin Durant blocked the most 3-pointers since 2007.

Alright, that's part 3 of this series. As always, feel free to leave a comment if you found anything interesting or if you think there's a better way I can look at things. In my next post, I'll take a look at how block value by shot location relates with block value by shot type and whether or not these values fluctuate from season to season for different players.

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