In last week's article about the midrange shot, this old argument reared its ugly head in the comments:
However, what if a team thinking to maximize their expected value simply stopped taking any shots that weren't 3-pointers or at the rim? So much so that an opposing team could rely upon those shots not being taken? In that scenario, the opposing team could change their defense to put all focus on 3-pointers and shots at the rim so that the expected value of those shots ends up much less than the average on which Wages analysis is based.
This has come up before. There is a ton of anecdotal and logical evidence that this is false. We're also going to be putting up a ton of emprical evidence that this is false, but not until after Sloan.
The obvious anecdotal counter to this argument is, once again, Houston. According to stats.nba.com, the entire Rockets team has taken 167 15-19 footers this year. To understand just how low that number is, consider that LaMarcus Aldridge has taken 303 all by himself. Further, note that every defense that plays against Houston knows that they won't try to get those shots; they only take them about 4 times a game, or on about 4% of possessions.
And yet the Rockets, playing against defenses that know exactly what they are trying to do, manage to shoot 47.2% (above average), 53.5% from 2 (significantly above average), almost average from 3 (34.2%) and the team achieves Jeff Hornacek's "magic" threshold of > 51% eFG (52.8% eFG), as well as a 56.7% true shooting mark (again, way above average). It's worth noting also that the Rockets shoot only 31% from 15-19 feet. This idicates that perhaps these are "desperate" shots taken when the clock is winding down; that would make sense given the frequency.
In other words, running an offense where you only shoot threes and layups does not appear to make it easier to guard that team. At least, it doesn't appear to make it easier to guard the Rockets. In fact, the opposite appears to be true. The main reason is that pretty much all NBA defenses already focus on 3-pointers and shots at the rim. It's not like teams march into Houston and the coach says "Hey guys, I know all year we've been saying we'll just let 'em fire from beyond the arc or under the basket, but tonight, we're going to defend the rim and the three-point shot!"
I'll re-iterate that we've got a lot of empirical data on this. The Rockets just provide an interesting natural experiment.
This is intuitive if you think about geometry; the area one needs to cover to guard mid-range jumpers is much smaller than the area you need to cover to guard 3 point shots. So it makes sense that defenses have to scramble lots to cover the whole three point line, and it further makes sense that the fact that when players aren't stopping to pull up from 16 feet when they drive, that doesn't actually help the defense; in fact, since most defenses are trying to make the offense do just that, the fact that a team like Houston is relentlessly trying to get the rim makes the defense work harder; defenders trying to "help the helper" or to rotate after a penetrate-and-pitch drive followed by a swing pass have to cover more ground when the ballhandler gets closer to the rim before pitching.
Of course, a team has to get players that are good at finishing at the rim and/or getting to the free throw line. Otherwise the "layup" part of the offense's threat is easy to prevent, and the helpers and rotaters don't have to scramble as much. This type of offense works well when you have James Harden. On the other hand, it's pretty clear that there are players with similar skillsets to Harden who could become more efficient by being more relentless with a "three or the rim" approach (Mr. Anthony, my gaze is fixed firmly upon you and your 203 midrange jumpers).