How Will Bohannon's Absence Impact Iowa on Each End of the Floor?

By houksyndrome on December 27, 2019 at 1:30 pm
go hawks go
© Brian Spurlock-USA TODAY Sports

Unfortunately, Jordan Bohannon will not be playing for the rest of the season.  Let’s see if we can guesstimate how things are going to go in his absence.  It comes down to a couple of simple questions (with not so simple answers):  who will get Bohannon’s minutes?  How will we do when those players are on the floor compared to when Bohannon was on the floor?

Let’s start by assessing what will happen to our rotation and minutes distribution moving forward, since that is the simpler one.  Bohannon was getting 25 minutes per game.  Going back to 2013-14, the most any of Fran’s players have averaged is 31.5 minutes per game.  Luka Garza and Joe Wieskamp are already at 30 minutes per game so they can’t get much higher.  C.J. Fredrick and Connor McCaffery are both at 27-28 minutes per game.  If we bump all of those players up to 31.5, that only covers about 11 minutes per game, so there’s still 14 more minutes to spare.  Personally, I don’t think we’ll play all four of them 31.5 mpg, instead it’ll probably be more like 30 mpg, leaving about 20 minutes to spare.

Those minutes will primarily go to Ryan Kriener, Cordell Pemsl, Bakari Evelyn and Joe Toussaint - each of whom are currently averaging 15 minutes or less per game.  Fran has a decision to make regarding whether or not we want to stick with the four guard lineups that we’ve been predominantly using since Nunge went down (i.e. lineups where Wieskamp and Connor are our two forwards).  If we stay with four guard lineups, then Evelyn and Toussaint will get more minutes.  If we go back to lineups with a traditional power forward, then Pemsl and Kriener will get more minutes.  I imagine that we’ll see an uptick in these bigger lineups but will still continue to use the four guard lineups more frequently.  The bottom line is this:  I think we will see an increase in minutes per game for Kriener, Pemsl, Evelyn and Toussaint.

What does that mean for the effectiveness of our team on each end of the court?  Obviously, it is impossible to know with certainty, but they pay us the big blog bucks to try anyway, so that’s what we’ll do.  There are five players who we need to consider:  Bohannon, Evelyn, Toussaint, Pemsl and Kriener.  There’s a few ways to evaluate the abilities of these players:  subjectively, by watching the games and forming our opinions of the players, by looking at box score based statistics or by evaluating how the team performs when each player is on the court, which is what I track when I watch the games.  To my knowledge, there is no other place on the internet to find that information.  These last two methods are objective but that doesn’t make them perfect.

By eye, I think that Bohannon is a great shooter, who takes good care of the ball, who knows what the plan is on each possession (i.e. feeding the post), and is good at making the post entry pass.  He’s also clutch.  In other words, he’s a very good offensive player (duh).  Subjectively, I would say that he is a much better offensive player than any of the guys that are replacing him.  Kriener seems to be hit and miss, Pemsl seems to be really struggling, Toussaint is quick but doesn’t seem ready for a big role yet, Evelyn has been invisible (except for the Cincinnati game, obviously).  The good news is that there are two ends of the floor and the strong consensus opinion is that Bohannon is not a great defender.  So, even though our offense is likely to take a hit without Bohannon, we might improve defensively.  To my eye, both Toussaint and Evelyn look like better perimeter defenders than Bohannon and I could also see increased use of a traditional power forward being a defensive improvement over our four guard lineups (due to more rim protection and defensive rebounding).

The questions become: how much better will we be on defense and how much worse will we be on offense?  My possession tracking data allow us to estimate this.  I’ve given a detailed explanation of my methods in previous articles but the bottom line is simple:  how many points do we score and allow, per possession, when each player is on the court?  The results are in Table 1 for each of the players under discussion, as well as the overall totals for the entire team.  Note: I did not include the Cincinnati game in this analysis.

Table 1: All games, excluding Cincinnati
Total 1.15 1.00
Bohannon 1.14 1.04
Evelyn 1.04 0.90
Toussaint 1.09 0.94
Pemsl 1.07 0.83
Kriener 1.08 0.99

There was one thing on this table that gave me pause:  overall, we scored 1.15 points per possession (PPP) but only scored 1.14 PPP when Bohannon was on the floor.  That doesn’t make sense.  I think it has to do with Bohannon preferably playing in closer games against stronger teams.  For example, Bohannon didn’t play at all against Cal Poly, a game where we were +0.36 PPP.  Pemsl didn’t play against SIU-E.  Let’s see what things look like when we omit the SIU-E, Cal Poly and Cincinnati games.  This is shown in Table 2.  Again, surprisingly, Bohannon’s presence on the floor did not give us a major boost on offense.  Our overall offensive efficiency is 1.13 and it is also what we scored when Bohannon was on the court.  I will discuss this in a bit more detail below.

Table 2: Excluding Cal Poly, SIU-E and Cincinnati
Total 1.13 1.04
Bohannon 1.13 1.06
Evelyn 1.00 0.95
Toussaint 1.06 0.99
Pemsl 1.05 0.89
Kriener 1.02 1.02

In tables 3 and 4, I show statistics called “O Diff” and “D Diff”.  “O Diff” is how many PPP we score when that player is on the court minus the PPP we score when that player is not on the court.  “D Diff” is how many PPP we give up when that player is on the court minus the PPP we give up when that player is not on the court.  You want the “O Diff” to be a large positive number and you want “D Diff” to be a negative number with high absolute value.


Table 3: All games except Cincinnati
  O Diff D Diff
Bohannon -0.01 0.11
Evelyn -0.16 -0.15
Toussaint -0.09 -0.10
Pemsl -0.10 -0.22
Kriener -0.12 -0.01


Table 4: All games except Cal Poly, SIU-E and Cincinnati
Bohannon 0.0 0.06
Evelyn -0.19 -0.13
Toussaint -0.10 -0.08
Pemsl -0.11 -0.20
Kriener -0.17 -0.03

The offense gets worse when Evelyn, Toussaint, Pemsl and Kriener are on the court, particularly Evelyn (again we are not factoring in his very good performance against Cincinnati).  Depending on the player, and the table, the offense is 0.09 to 0.19 points per possession worse when any of these four players are on the court.  I think our days of being the most efficient offense in the nation are over.  However, our defense has been 0.08 to 0.22 points per possession better with any of Evelyn, Toussaint or Pemsl on the floor.  My possession tracking does not look on Kriener very favorably; however, to my surprise, it suggests that there won’t be much of a drop off between Bohannon and Evelyn / Toussaint / Pemsl because their differential effects on our offense and defense will more or less cancel out.  In particular, our defense is strikingly better when Pemsl on the floor.

One gigantic caveat of all this is whether these rates will continue when Evelyn, Toussaint and Pemsl are playing larger roles.  A number of things factor in but one of the big ones is that our backups are usually playing against the other teams backups and now they will increasingly be going up against the other team’s starters.  I also have a fairly small sample size at present, especially for Pemsl, for whom I’ve only got about 180 possessions.  As players get more minutes fatigue becomes more of a factor as well.  However, with more usage, these guys might get into more of a rhythm on offense.  We may have already seen that with Evelyn’s performance against Cincinnati.  So the extrapolation could go either way and we’ll just have to see what happens.  But there is reason for hope and we shouldn’t be shocked if our defense improves substantially over the remainder of the season.

You might have noticed an oddity in these data.  The offensive efficiency doesn’t change much when Bohannon is out of the game, but it seems to go way down when his replacements are in the game (i.e. Evelyn, Toussaint, Kriener and Pemsl).  Why is that?  The answer is that those aren’t the only guys who have been playing in Bohannon's absence this year.  For example, when Nunge or Pat McCaffery played this season, we put up 1.19 PPP and 1.14 PPP on offense, respectively.  That was primarily against weak opposition and it has no bearing for the rest of the season since Nunge is out for the season and Pat's status for the rest of the year is very unclear.  The only reason I bring it up is to justify an apparent discrepancy in my data.  The bottom line is that everything is okay and I didn’t mess up my spreadsheets.

Finally, let’s discuss why Bohannon wasn’t making such a huge impact on offense.  The answer to this is simple:  shooting.  Bohannon hasn’t been himself shooting the ball.  He only made 33% of his three point attempts this season and a brutal 22% of his two point attempts.  His assist and turnover numbers were good and he was perfect at the FT line.  He was just in a slump on his field goal attempts.  I’m sure that, over a sufficient number of attempts, a healthy Jordan Bohannon is a 40+% three point shooter.  However, he wasn’t healthy and his shot wasn’t as accurate as it normally is.  Yet we were still one of the best offenses in the country.  The fact that our offense has been this effective despite Bohannon’s shooting slump is a reason for optimism, both in terms of our ability to survive his absence this season and for next year, when he should finally be healthy.

View 2 Comments