Shot quality and the Louisville Cardinals
What a new metric tells us about the Cards
One of my favorite things about basketball is that there’s really not much subjective about it. There’s no points for degree of difficulty or style or aesthetics. Results are purely determined by a math question: did you score more points than your opponent or not?
Results of any one game have a high degree of randomness in them, however. Even a team that’s 2-15 can have some games where they hang right in with a better team until the buzzer (Syracuse) and some where they get blown out by an otherwise lousy team (Florida State). The main culprit of this randomness is shooting variance, or shooting luck. Sometimes you just go 3-20 on threes, and sometimes you go 11-20.
The basketball data company Synergy recently added metrics to evaluate shot quality based on the expected points created by a shot, factoring in shot location, player, and defender location. For example, an unguarded catch-and-shoot three by JJ Traynor might be expected to go in 38% of the time, so that would be worth 1.14 points (3pts x .38). A 6 foot hook shoot by Sydney Curry might go in 45% of the time, so that would be worth 0.90 points (2pts x .45). Synergy has a database of the expected points of all shots this season, and classifies the bottom 20% of shots as Low Quality, the top 20% as High Quality, and all others as Medium Quality.
Shot quality data and trends can be very informative. Synergy’s data can help identify what types of offensive sets generate more high quality looks, or which players take a large portion of low quality shots, or whether team shot quality is improving over time. In this article, I’ll use Synergy’s shot quality data to identify some insights about Louisville’s team and individual players.
Before I get into this article, I’d encourage subscribers to catch up on some past articles I wrote which are particularly relevant given UofL’s performance in recent games:
A profile of Mike James from Dec 4th where I made the case that James needed to be a bigger part of the offense due to his efficiency
An overview of UofL’s offense from Dec 27th where I highlighted how the Cards are better with just 1 big and lineups with more shooters, but they’d been stranegly reluctant to play them
For premium subscribers: evidence that Louisville is starting to make things easier on themselves on offense, plus which player is making the most of tough shots?
Improving shot quality
Louisville is probably not going to stop turning the ball over a ton this season. They also probably aren’t going to improve a ton defensively. The Cardinals have started show improvement on offense, however; specifically, in shooting. Louisville’s effective field goal percentage has been at or above 49% for each of the last 5 games. That’s not a high bar, but over the first 12 games they only exceeded it 3 times (Bellarmine, Wright State, Western Kentucky). Over that 5 game stretch, Louisville’seffective Fg% ranks 150th in the country, per Bart Torvik. The Cards were 330th over their first 12 games, so that qualifies as significant improvement.
Synergy’s data indicates that Louisville is taking more high quality shots and fewer low quality shots than earlier in the season:
UofL’s portion of shots classified as “Low Quality” has dropped from 31% to 23%, and the portion classified as “High Quality” has jumped from 11% to 21%. That’s a really significant improvement and a sign that Louisville is not just getting lucky, but legitimately putting together somewhat competent shot selection.
What’s really interesting is the types of shots they’re getting more of that are classified as High Quality. A High Quality shot is a pretty high bar to hit, and the shots need to have an expected value of about 1.30 points to earn that label. A 3 pointer would need to go in about 43% of the time, or a 2 pointer about 65% of the time, in order to meet that threshold. While the Cards are hitting 39% on threes over the last 9 games, those aren’t the shots Synergy is counting as high quality….it’s more open shots around the rim. Those shots are coming in halfcourt offense, and it’s largely due to better halfcourt spacing drawing defenders away from the rim. If Mike James, Jae’lyn Withers, or another Cardinal is able to get by their defender, the help defenders are farther away and Louisville is getting 3-4 more open layups at the rim each game. That’s not a huge number, but that plus better shooters on the perimeter add up to an offense that is no longer an abomination.
One player in particular making the most of bad shots
Another useful way to use shot quality data is to compare how often various players are taking low quality shots vs high quality ones. There’s a lot of context to consider when looking at these numbers, but here’s the data for Louisville so far this season:
Here are the takeaways that I think are important:
Mike James and JJ Traynor take a far lower % of low quality shots than their teammates, which makes them extremely valuable to the offense. Curry and Huntley-Hatfield do too, but that’s largely because they aren’t shooting unless they are near the basket. Despite Huntley-Hatfield’s large number of high quality shots, he has a low effective FG%, indicating he’s missing a lot of quality shots. Could be bad luck, or trouble converting around the rim.
Kamari Lands is having a rough season on offense, taking an above-average share of shots (if 5 players are in the game, each should average 20% of shots if all is equal) while shooting very poorly. He takes very few high quality shots, as he struggles to get to the rim.
El Ellis and Jae’lyn Withers have the largest share of shots, and both end up taking a lot of low quality shots when teammates can’t come up with anything. Despite this, Withers’ effective FG% is much better than Ellis’, indicating that Withers is doing a better job of converting tough shots (or getting lucky!)
In fact, Withers stands out on the team as having a respectable effective Fg% despite relatively low shot quality. This also shows up when comparing the points per shot for each player to their expected points per shot:
Withers and James are both exceeding the expected points on the shots they take, and Withers is managing to do so on shots that would be expected to yield very little. His shots are not much higher quality than Ellis’ but Withers scores 0.13 pts/shot more than Ellis. On the flip side, Lands and the little used rotation players underperform their expected points per shot by huge amounts. This could be bad luck, or could indicate that they lack much shotmaking ability. Given their limited resume in college I don’t think this means they can’t be D-1 players, but they definitely have a lot of work to do in order to become positive contributors on offense.
Given the data above, it’s not surprising that lineups with James, Withers, Traynor, and a big (usually Curry) are the most effective on offense. They have proven to be capable shotmakers on offense, and they create a complementary identity on offense of spacing the floor with reasonable shooters while creating lanes for attackers (Ellis, James, Withers) to get to the basket. Combine that with Curry’s effective shooting around the basket and relatively low shot volume, and Louisville can actually put together some solid offensive stretches.
Earlier in the season Louisville was offensive in a different way, as they didn’t look like they could field an ACC-caliber team. They may not win many more games this season and their defense and turnovers may keep them from fully looking the part, but the Cardinal offense can keep them competitive in a fair number of conference games. Given where things were in early December, that’s progress. There’s a lot of work to do if the program will be rebuilt, but steps are being taken in the right direction.