Derrick Williams is the most highly touted prospect in this group, and his situational stats do nothing to diminish his standing.
Williams shouldered a heavy load for Arizona this season at 16.4 possessions per game (5th in this group), but was nevertheless the most efficient forward of the players we looked at, scoring 1.16 points per possession. That's especially impressive considering how heavily defenses keyed in on stopping him, how little playmaking Arizona had besides him, and the way in which he generated his offense.
In fact, Williams' offensive efficiency ranks higher than every other player in this draft besides Jon Diebler (1.3 PPP) and ironically enough, fellow #1 overall pick candidate Kyrie Irving (1.2).
The key to Williams' efficiency begins with his ability to get to the free throw line, where he knocks down 75% of his attempts. He got to the free throw line on over 1/4th of his possessions, which ranks 2nd in this draft behind Tristan Thompson.
Williams may not shoot the most jumpers of this group—only 25% of his shots come in this form-- a far cry from Kyle Singler and Robin Benzing at 63% or Chris Singleton at 56%-- but he makes more of the jumpers he does take (56%, or 1.6 points per shot) than anyone, and not by a small margin.
Williams appears to do a great job trusting Arizona's offense and waiting for good opportunities to come to him rather than hunting shots—something that his NBA coach will surely appreciate. Williams amazingly enough only took 5 pull-up jumpers all season, representing just 1% of his total offense.
This can be viewed as either a positive or a negative. On one hand he refused to settle for these low-percentage opportunities (which with the shorter 3-point line, are truly bad shots in the collegiate game). On the other hand, this may be a part of his game that he'll need to work on, particularly if he's expected to create offense from the perimeter in the NBA as heavily as he did in college.
Williams was indeed one of the most dangerous shot-creators in the college game amongst big men (he played almost all his minutes at Center at Arizona), scoring an outstanding 1.3 points per possession (#1) in isolation situations and getting fouled on nearly a third of his possessions (#1). By comparison, the next most effective isolation threat in this group, Kyle Singler, scored just .99 points per possession, getting to the free throw line at half the rate. None of the other first round prospects were anywhere near as effective.
This did come at the expense of turning the ball over on 16% of his possessions (3rd), though.
Williams' versatility shines through in the rest of his game, as he did an excellent job scoring in post-up situations (1.06 PPP), pick and roll finishes (1.37 PPP), and cuts (1.26). Some of the credit for this should go to Arizona's coaching staff, which obviously knew precisely how to exploit Williams' strengths and did a great job putting him in position to succeed.