Summary
Throughout his career, Len has been a decent backup center at best, and is moving to the stage of his career where he is likely a third center. He has some skills on offense, and even started to shoot threes later in his career (although that has tailed since his days in Atlanta). He has nice touch inside, and hit 78% of his shots at the rim in '23-'24 in limited minutes, but has been up and down in that regard throughout his career. Len has put up good offensive rebounding numbers for most of his career, which allows him to feed off of putbacks. 

He's serviceable on defense, although nobody would call him an intimidating rim protector. He has a decent block rate and knows how to use his big body inside. However, he's not very quick laterally, and doesn't have much hope of success if he is forced to defend on the perimeter. He isn't the most disciplined defender, and is pretty foul prone.

Despite not having many clear weaknesses, Len also does not have a key NBA skill that guarantees he will stick around in the NBA. He barely played for the Kings in '22-'23 during the regular season, but actually had some solid moments in the 2023 playoffs. He got more minutes in '23-'24, but was still not a regular part of the rotation.

​Len will be 31 years old as a free agent in 2024, and I would expect him to be a minimum-contract guy going forward. He may be able to stick around for a bit as a reliable veteran that can fill in during the regular season when guys are injured, but there's also a chance that he could be out of the league soon.
 
Cap Considerations
Len will be an unrestricted free agent with a $2.1 million cap hold and full Bird Rights, so the Kings will have no restrictions on re-signing him.

Other teams will have multiple ways to sign Len as even teams without cap space could possibly use any of the Non-Taxpayer MLE, Taxpayer MLE, Room MLE, or Bi-Annual Exception to sign him. It's also likely that Len only gets minimum offers, and may not get fully-guaranteed offers.