The Lawson Effect

Ty Lawson of the UNC basketball team has missed several games this season and he is currently injured. UNC clearly hasn't played as well with him gone. Points per game have gone down and turnovers have gone way up. Let's have a little look into how he affects the Heels from a statistical point of view.

The best place to start is with Ken Pomeroy because he runs an excellent college basketball statistics site. I have taken the follow numbers from his UNC Game Plan page

Here is a chart I made detailing UNC's offensive (pink) and defensive (blue) efficiency. Efficiency is basically a measure of how many points you score per possession. You want a high offensive efficiency and a low defensive efficiency (points allowed per possession).


As you can tell, the last couple of games, Lawson has been missing and the offensive and defensive efficiencies are nearly equal, and the scores reflect that as we've played very close games. There is also a large drop in offensive efficiency in late November when Lawson missed games against BYU and Ohio State (he played 2 minutes against BYU before being injured, so I'm not counting it).

To better determine Lawson's effect on the team, lets look at the overall season averages, conference averages, averages with Lawson, and averages without Lawson. Any game where Lawson only played a few minutes and then left due to injury was counted as game without him. Explanation of the columns is available here.

		Offense
	Pace	Eff.	eFG%	TO%	OR%
Sea. avg	76.36	115.48	52.26	18.42	42.26
ACC avg	75.00	110.92	49.16	19.03	41.86
w/Lawson	77.26	119.98	54.01	17.67	43.52
w/oLawson	73.50	101.25	46.72	20.82	38.28

	Defense
	Eff.	eFG%	TO%	OR%	FTR
Average	94.05	48.32	20.96	28.40	23.71
ACC	100.49	48.92	17.07	29.63	24.57
w/Lawson	93.97	49.08	22.08	28.45	25.27
w/oLawson	94.32	45.92	17.40	28.23	18.75

This offers some more insight into where Lawson matters most. Here are some of the notable differences in playing without Lawson:
On Offense:
- UNC has about 4 fewer possessions per game
- UNC's offensive efficiency is much lower, going from about 1.20 points per possession with him to only 1.01.
- Effective field goal percentage (values 3 point shots 50% more than 2 pointers) drops from 54.01 to 46.72
- The number of possessions on which we turn the ball over increases from 17.67% to 20.82%.
- One thing that is a bit confusing is that with Lawson, a 5'11'' point guard, we do a better job of collecting offensive rebounds than without him: 43.52% to 38.28%
- Our free throw rate is about the same on offense, 40.31 with Lawson to 39.63 without him.

On Defense:
- Our defensive efficiency is about the same, 93.97 with to 94.32 without
- Curiously, opponents shoot better when Lawson is playing: 49.08% with to 45.92% without.
- However, opponents turn it over more frequently against Lawson: 22.08% with to 17.40% without
- Opponents have the same offensive rebounding rate with or without Lawson playing; however, they do have a slightly better free throw rate when Lawson plays.

Conclusions:
Obviously, we're really hurting offensively without Lawson. Anyone watching recent games could tell you that. It's impressive that almost all of our offensive numbers are better (except FTR) with him playing, even offensive rebounding.

On the other hand, our team doesn't seem to be suffering much from his absence on the defensive end. UNC doesn't create quite as many turnovers and opponents make more free throws, but their field goal percentage drops.

On the whole, the extra playing time for Quentin Thomas may help to make UNC a more complete team in the future. From here on out, all the games are against high quality competition.