Franalysis: How Bad Is Iowa’s Defense — And How Could Iowa Try To Fix It?

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Happy New Year, folks and welcome to my first attempt to analyze Iowa MBB in 2022!  Iowa currently sits at 11-4 (1-3 in Big Ten play) with all four of its losses coming to very good teams (three on the road, no less).  On the other side of the coin, eight of those eleven wins have been against cupcakes with Pomeroy rankings of 200 or worse.  Iowa is 3-4 against teams with a pulse; the three wins are against Virginia (road), Maryland (home) and Utah State (neutral) — ranked 63rd, 68th and 66th, respectively, by Pomeroy.  Roughly speaking, Iowa has beaten the teams they were supposed to beat and lost to the teams they were supposed to lose to. 

Ken Pomeroy and Bart Torvik both think we are pretty good, ranking us 25th and 31st, respectively.  To my knowledge, neither of those ranking systems are used by the selection committee; however, teams with Top 30 Pomeroy/Torvik rankings almost always make the NCAA tournament.  Pomeroy projects an 11-9 Big Ten record while Torvik projects 10-10.  Iowa would have a very good shot at making the tournament with either of those records which would be a nice accomplishment for this team given what it lost in the offseason.

The questions therefore become things like: is the Pomeroy ranking accurately assessing the quality of this team and will Iowa be able to maintain this ranking throughout Big Ten play by winning ten more Big Ten games?  Nobody knows the answer but I am more than a bit worried that, although Pomeroy and Torvik adjust for strength of schedule as best they can, the cupcakes weren’t strong enough opponents to expose the weaknesses of this team. 

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Bart Torvik has a “Game Score” metric which estimates how well you have played based on your points scored and allowed per possession, adjusted by the quality of your opponent’s defense and offense.  In Iowa’s eight games against cupcakes, that game score was a very nice 89.  However, in the seven games against quality opponents, it is a worrisome 72.  Thus I fear that the blowouts over the cupcakes are skewing Iowa’s Pomeroy/Torvik ratings and causing them to overestimate the quality of this team.  Although the aforementioned ranking systems project Iowa as a NCAA Tournament team, I think Iowa will have to improve if they are to reach the 10-10 conference record which is usually required to go dancing.

There is little room for this team’s offense to improve as it is already ranked 3rd, nationally, by Pomeroy and 4th by Torvik.  Only two opponents (Purdue and Iowa State) have managed to hold Iowa to less than 1.0 point per possession.  Keegan Murray didn’t play at all against Purdue and his injury likely contributed to his struggles at Iowa State (although the Cyclones’ outstanding defensive performance was also a major factor).  The offense is not the problem here.  The problem is, YOU GUESSED IT!, the defense. 

Iowa’s defense is ranked 156th and 181st by Pomeroy and Torvik, respectively.  That isn’t quite as bad as the stink bomb that the 2017-18 team dropped (242nd defensively, per Pomeroy) but it is still really bad.  If it holds up, this would be the third worst defensive team of the McCaffery era behind the 2011-12 and 2017-18 teams.  The last two seasons have seen Iowa produce some of the greatest offensive performances in program history, only to be undermined by mediocre-to-poor defense — but those teams still had top-100 defenses, considerably better than the defense of this year’s team.

Here is how Iowa is performing this season (national ranking shown) in each of the four factors (statistical categories that determine effectiveness), compared with some previous seasons:

Iowa’s national defensive ranking in each of the four factors
YEAR OVR DEFENSE eFG% TURNOVER RATE DEF REB RATE FREE THROW RATE
2021-22 156 144 104 262 118
2020-21 75 114 311 219 6
2019-20 97 169 248 251 50
2018-19 111 206 173 230 72
2017-18 242 274 324 141 47

Keep in mind that the four factors are not adjusted for schedule strength and the data from previous seasons was against the entire schedule whereas, for this season, Iowa has yet to play most of its Big Ten schedule.  So the four factor rankings are actually worse than they appear, compared to previous seasons, because over half of Iowa’s games so far have been against cupcakes.

As you can see Iowa is forcing turnovers better than usual but is quite a bit worse than usual in the other categories.  Opponents are shooting well against Iowa which is primarily being driven by success on two pointers (49.5% from the field, 180th nationally).  As a team, Iowa is blocking 12.2% of opponents’ two point shots, which is respectable (63rd nationally), but that is being entirely driven by the Murray twins.  None of the other rotation players block any shots to speak of.  As a result, opponents are getting easy baskets around the rim when the Murrays are either on the bench or defending the perimeter.   

Iowa has normally been very good at keeping the other team off of the free throw line but this year’s team has taken a major step back in that area (the current ranking of 118th would be the worst of the McCaffery era, surpassing the 2011-12 team’s ranking of 81st).  The biggest culprits (among rotation players) are Kris Murray, Filip Rebraca, Tony Perkins, and Connor McCaffery who commit 4.7, 4.4, 4.2 and 4.0 fouls per forty minutes, respectively.  Against quality opposition, those players are fouling at even higher rates of roughly 5-8 fouls per forty minutes.  If this group of players could reduce their fouling rate, that would help quite a bit.

Iowa’s worst statistical category is defensive rebounding.  Under Fran, the Hawkeyes are usually considerably worse on the defensive glass than they are on the offensive glass but the defensive rebounding is particularly egregious this year.  It would be great if Pat McCaffery could provide more help on the defensive glass — he is averaging only 3.6 RPG which is very unimpressive for a guy who is 6’9″.  I think the defensive rebounding, rim protection, and fouling problems all stem, at least in part, from being undersized.  So one option would be to give the young bigs (Riley Mulvey and/or Josh Ogundele) increased playing time.  Another option would be to employ a front court of both Murray twins + Pat McCaffery which, while lacking a true center, does make up for it with length and athleticism at both forward spots (more on this later).

+/- Data Against Quality Opponents

If you’ve been reading my pieces for a while, then you know that I keep track of how the team does whenever each Iowa player is on the floor.  In the following table, I present those statistics:  the points allowed per possession (D PPP) and the points scored per possession (O PPP) when each of Iowa’s player is on the floor.  I also calculate “D Diff” and “O Diff,” which is the amount that Iowa’s D PPP or O PPP changes when a particular player is in the game.  A large negative D Diff means that the defensive efficiency improves when the player is in the game while a large positive O Diff means that the offensive efficiency improves when then the player is in the game.  With that explanation out of the way, let’s dive into the data from Iowa’s seven games against quality competition (the six games vs Power 5 opponents + Utah State).

Points Scored and Allowed Per Possession
Player D PPP O PPP D Diff O Diff
Toussaint 1.24 1.15 0.16 0.07
Bohannon 1.22 1.14 0.17 0.07
Keegan Murray 1.21 1.15 0.19 0.11
Pat McCaffery 1.17 1.12 0.03 0.00
Rebraca 1.22 1.23 0.14 0.24
Connor McCaffery 1.06 1.02 -0.16 -0.15
Perkins 1.13 0.99 -0.05 -0.23
Sandfort 1.19 1.05 0.04 -0.07
Kris Murray 1.02 1.11 -0.25 -0.01
Mulvey 1.29 1.10 0.14 -0.02
Ogundele 1.17 0.88 0.02 -0.27
Ulis 1.04 1.16 -0.20 0.09

This is a defense-focused article and there are three players whose “D Diff” stat really stands out:  Ahron Ulis, Connor McCaffery and Kris Murray.  Iowa has been allowing 0.16 – 0.25 fewer points per possession when any of these three players are on the floor.  Obviously, caveats apply to this type of data since it is inherently correlative.  We don’t know if Ulis himself is the reason that Iowa is allowing fewer points when he’s in the game — part of it could be due to him playing more minutes against the other team’s backups whereas Toussaint is playing more minutes against the other team’s starters.  To my eye, Toussaint is a better defender than Ulis, but these data are what they are and Fran may want to try increasing Ulis’ and Kris Murray’s minutes to get some defensive improvement.  Fran could also increase Connor’s playing time but, so far, the increased defensive efficiency has been cancelled out by reduced offensive efficiency when Connor is in the game.

This brings me to the final section of the article:

What can Fran do to get better defense?

  • Play Ulis more.  The backcourt combination of Ulis+Bohannon is currently scoring 1.23 PPP and allowing 1.02 PPP.  The backcourt combination of Toussaint+Bohannon is scoring 1.18 PPP but allowing 1.31 PPP.  When Toussaint is on the floor without Bohannon, Iowa is scoring 1.0 PPP but only allowing 0.83 PPP.  It’s hard for me to buy the idea that Toussaint, of all people, is the source of Iowa’s defensive problems and the data set is small and caveat-riddled.  Still, this defense is so bad that Fran should be willing to try anything, including giving Ulis more time with the starters.
  • Play both Murray twins simultaneously.  Iowa is scoring 1.11 PPP and only allowing 1.0 PPP when both Murrays are on the floor together (~115 possessions).  Let’s see more of that combination, please.  Also, when Rebraca is out of the game, I’d like to see both Murray twins on the floor together along with Pat McCaffery.  Those three players have only logged 30 possessions together against quality competition but they’ve scored 1.31 PPP and only allowed 0.64 PPP in that time.  That combination is worth exploring further.
  • Play Ogundele and/or Mulvey more.  The +/- data don’t exactly scream “PLAY THESE GUYS.”  Obviously, they are raw and there will be growing pains (for example, they are both fouling machines with ~6 fouls each per 40 minutes).  Playing them could cost Iowa a game or two in the near term, but they might also be the only hope of solving Iowa’s interior defense and rebounding problems by the end of the season.
  • More press.  Iowa’s man-to-man defense is allowing 1.2 PPP and the zone has been even worse, allowing 1.27 PPP.  However, on possessions where Iowa presses (regardless of what defense they fall back into after the press), they are only allowing 1.05 PPP.  Would that hold up if Iowa used it all the time?  I don’t know but it’s reaching the point where Iowa probably ought to experiment with this.
  • Figure out the end of the first half.  During the last ~4 minutes of the first half, Iowa is scoring a mere 0.84 PPP while allowing 1.37 PPP.  During the last two minutes of the first half, they are allowing 1.61 PPP.  Games are slipping away from Iowa during this crucial stretch and it needs to be addressed.  This might be a good time for both Murrays to be in the game together.

 

Keegan Murray is having a marvelous season and it would be a shame if he didn’t get to cap it off with an NCAA Tournament appearance.  Getting there will require Fran to get this defense into a passable state.  Here’s hoping he figures out how to do that, starting with tonight’s game against Indiana.  Go Hawks!