clock menu more-arrow no yes mobile

Filed under:

Why True Shooting Percentage is a statistic you might want to care about

Checking into more advanced statistics and why they matter.

NCAA Basketball: NCAA Tournament-First Round-Missouri vs Florida State Christopher Hanewinckel-USA TODAY Sports

At its most basic level, the game of basketball is very simple: you try to put the basketball into the hoop and do your best to prevent your opponent from doing it.

The more layers you add, though, the more intriguing the game can get.

For the longest time, stat-keeping for basketball was simple as well. Traditionally the marker for good shooting was through the field goal percentage statistic. It was simple: how many shots you made divided into how many you took.

The advent of the 3-point line made this marker a little less useful, though, as some baskets were more valuable than others. Then someone also realized that FG% doesn’t really take into account free throw shooting. Thus, True Shooting Percentage was born!

Exciting inception story, right?

Here’s why it's important... and we’ll use Missouri players from last year as an example.

Field Goal Percentages

Player FG% 2FG% 3FG% FT%
Player FG% 2FG% 3FG% FT%
Jeremiah Tilmon 56.40% 56.40% - 52.60%
Jordan Barnett 44.90% 50.80% 41.40% 89.00%
Kevin Puryear 44.10% 50.00% 25.50% 82.40%
Jontay Porter 43.70% 50.00% 36.40% 75.00%
Jordan Geist 43.70% 51.90% 36.70% 70.00%
Kassius Robertson 42.20% 40.50% 43.20% 79.50%
Michael Porter, Jr. 33.30% 35.00% 30.00% 77.80%

By looking at overall FG%, sorted by highest to lowest, you would think throwing the ball to Jeremiah Tilmon as often as possible would make the most sense. He, after all, was the most efficient Mizzou player at making shots.

Of course, Tilmon was taking 2-point FGs exclusively, plus he isn’t a good free throw shooter and had a high turnover rate. That caused his general efficiency to suffer.

Tilmon didn’t attempt a single 3-point shot last season; meanwhile, the Tigers were a top-30 team in the amount of 3-pointers per possession they attempted. It’s easy to see how more advanced shooting numbers could impact the approach to analyzing the team.

A quick explainer on True Shooting Percentage and how it’s calculated:

The idea is to weight points based on overall attempts, with free throws factored in. The formula is:

Points / (2 * (FG Attempts + 0.44 * FT Attempts))

The 0.44 comes from the fact that not all free throws add up to a full possession, whereas a field goal attempt does add up to a full possession. So essentially true shooting is your shooting percentage, only more on a per-possession basis.

A quick explainer of Effective FG% and how it’s calculated:

The idea behind eFG% is to properly weight 3-point shooting by awarding a made 3-pointer 1.5 times more credit than a 2-pointer (since it’s worth 1.5 times more).

(2PT FGM +( 1.5*3PT FGM)) / FGA

eFG is a simpler formula and doesn’t weight free throw shooting into a shooting percentage. It makes sense in a way but downplays the emphasis on a per possession basis.

A quick explainer on Offensive Rating and how it’s calculated:

Offensive Rating is the most all encompassing and complicated of all of these advanced statistics because it looks at every way a player can impact a possession and removes tempo by factoring it by 100 possessions total. It includes assist rate (basically the assists per possession that a player generates when on the floor) and turnover rate (the same as assist rate, just with turnovers), plus the ability to score the ball.

(Points Generated / Possessions) x 100

A possession can be ended by taking a shot, turning the ball over, or committing a foul. So the Offensive Rating is something that isn’t easily calculated but tells you how much a player is worth on a per possession basis.

Advanced Field Goal Percentages

Player TS% eFG% ORtg
Player TS% eFG% ORtg
Jordan Barnett 61.80% 57.90% 120.3
Kassius Robertson 60.60% 56.30% 114.1
Jordan Geist 57.70% 53.60% 109.5
Jontay Porter 56.70% 52.10% 109.3
Jeremiah Tilmon 56.20% 56.40% 93.7
Kevin Puryear 54.50% 47.20% 105.1
Michael Porter, Jr. 43.80% 38.30% 92.3

Immediately with the advanced statistics, you see the two players who provided the most value to Missouri last year: Jordan Barnett and Kassius Robertson. They just jump off the page with their numbers. Barnett’s 1.20 points per possession (PPP) was 143rd in the country. Robertson’s was an excellent 1.14.

Meanwhile, the Tigers’ FG% leader Jeremiah Tilmon came in next to last on the per-possession basis.

Tilmon was good when getting shots, but Mizzou’s best possessions last year were those producing a Barnett or Robertson 3-point attempt. When Barnett took a 3, Mizzou averaged 1.24 PPP. For Robertson, that bumps to 1.30. A Tilmon shot attempt, meanwhile, netted 1.12 PPP — still good, but not as good as Barnett & Robertson.

NCAA Basketball: Missouri at Texas A&M C. Morgan Engel-USA TODAY Sports

Nobody is saying we should abandon watching games and just look at stat sheets from here on out.

In fact, it’s the opposite. Understanding these statistics and their usage makes watching games and offensive sets easier because you better understand the purpose.

It’s easy to watch Houston or Golden State play and understand why playing with tempo and offensive efficiency is important in today’s game. Corner 3s and elbow jumpers don’t have the same return on investment as a post up.

You see Jontay Porter play basketball and it’s, at times, something to behold because he does 100 different things on a given offensive possession, things Tilmon and Puryear and other more traditional bigs don't. A less advanced analysis of Porter would want him on the block with his back to the basket.

You watch Porter with his back to the basket and it’s easy to see why he passes out so frequently. In this exchange between Zach Lowe and Brad Stevens, it might help explain why:

Analytics folks say the post-up, or at least a post-up shot, is a low-efficiency play. But there’s a way to reconcile that, right?

There are two ways to get inside-out: driving or posting.

In other words: The post-up is more a vehicle for passing and other shots, rather than necessarily for a post-up shot itself?

It’s a vehicle for playing inside-out. That’s right.

The post-up as a scoring opportunity for most bigs these days is a waning idea. Basketball hasn’t changed — you still want to play inside out. You still want to take shots which will net you points more often than not. It’s just our understanding of which shots are efficient that has changed. Using TS%, among other stats, has helped us come to this understanding.