K.J. Adams’ Defense

After Jalen Wilson departed for the NBA and KU picked up 7’1 center Hunter Dickinson in the portal, K.J. Adams shifted his position from the 5-spot to the 4-spot in KU’s starting line-up. This shift has been seen on both ends of the floor. Offensively, he’s posting up less and making more plays on the perimeter as a creator (where he’s third on the team in assists). And while he doesn’t have what one would call “range,” he’s been making some mid-range jumpers and push-shots with Hunter underneath to rebound, which is what a traditional 4-man does when he is playing with a true 5-man.

But it is K.J. Adams’ defense which has been the most-valuable part of his game with his switch to the 4-spot. Last season, as someone primarily guarding the opposing 5-man at a height and length disadvantage, Adams was basically a neutral-value defender, finishing with a Per100 points-against bubble of -0.22. He gave up 12.7 points per 60 possessions (worst among the starters) as he had to battle inside. (Adams was able to benefit by having a slower player on him on the offensive end, so he did finish as a positive-value player overall (+0.49 per game)). In 2024, Adams is KU’s strongest defender, with a +5.01 Per100 value. And while his rebounding hasn’t really improved, he is giving up only 7.7 points per 60 possessions now that he’s guarding mostly wings and forwards. This defensive stinginess not only leads the team, but is close to the range of what KU’s best defenders have allowed over the past decades.

Since 2018, we have tracked defensive value at detailed-enough level to estimate which players were the best at not allowing points to be scored. This is seven seasons of data, including 2024. In this time, only three times has a player been a stingier defender than K.J. Adams this season. Marcus Garrett (2020 and 2021) accounts for two of these seasons. The other, which you wouldn’t probably guess correctly if you had 20 chances, was Isaiah Moss. While Moss didn’t rebound or force turnovers, he stayed close to his man and didn’t overhelp. Overhelping, particularly off wing shooters, is where many teams lose defensive value. Completely leaving one’s man should only be done to prevent an uncontested layup or wide-open 3 by a good shooter. Moss wasn’t overly athletic, but he had a high BBIQ as a veteran defender.

But back to K.J. K.J.’s value on the defensive end is estimated to be +5.01 points above that of a bubble-level player Per100 possessions. If we look at this from a per game ratio, then Adams is producing an estimated +2.91 points of defensive value above a KU-caliber replacement. According to current information, this would put him as having the 7th-best defensive season in the last 32 seasons (there have been 453 player-seasons in that time. K.J.’s 7th of 453).

That’s rather incredible. Whenever K.J.’s defense is talked about by fans, it’s often derided due to him not getting enough rebounds or having “short arms.” It’s true he doesn’t add value through rebounds or forcing turnovers. But he does an excellent job of not giving up easy scoring opportunities. He uses his strength to guard bigger players and his quickness to stay in front of guards. This versatility means he can easily switch positions 1-4 (and as we saw last season, can also play some against 5’s without being dominated). In turn, this forces teams to over-pass or take a less-than-ideal shot on certain possessions. All of this shows up in the numbers when we chart each defensive possession.

Note that these value estimates aren’t an exact science. Other sources don’t see him as having this much defensive value. Hoop-explorer doesn’t see much difference (although it relies on On/Off data which is very noisy and probably not wholly accurate). Evan Miya, which uses On/Off data and attempts to normalize the relative strengths of the other 9 players on the floor, has him as KU’s fourth-best defender. Without being overly critical, this seems to discount the on/off method for assessing player value. It isn’t K.J.’s fault if another teammate blows a defensive assignment when he’s in the game. While, with enough of a sample size, this “noise” would eventually even itself out (theoretically leaving you with just the player’s impact), it doesn’t seem to be the case unless there is a much larger sampling of minutes played. While K.J. has played 840 minutes so far, this only leaves 165 which he is on the bench. On/Off here isn’t really helping.

In 25 games this season, K.J. has posted positive defensive-scores in 21 of them. Teams aren’t attacking him much (like they would last season if they had a capable big). This means he’s doing his part. KU’s had defensive lapses, particularly among ball-screen coverage, but this is mostly due to Hunter being out of position (KU would do better to drop him rather than have him hard-hedge) or a separate wing/guard not being good at rotating over. K.J.’s fewest minutes in a game came against Chaminade, after he arrived following the death of his mom and didn’t start. He wasn’t expected to play, but did get on the court for 26 minutes and produced a small positive amount of defensive value. Self clearly wanted him on the court despite the opponent being a Division II team. This is further evidence that his defense warrants playing time, and is thus valuable.