For a guy considered such a liability in his own end, other teams sure have a difficult time scoring goals (and creating high danger chances) when he is on the ice the last couple years. Lets give it another year before we pass judgement I guess but if he continues the same trajectory he is on, the Oilers are going to be very happy with that contract, especially if he can continue to produce 5v5 points.
If you break down Ceci's performance at the beginning of the season when he was getting 3rd pairing sheltered minutes, versus later in the season when he got bumped up to the Pens' 2nd pairing when Marino started to struggle and got reduced minutes, you'll notice the drop in overall performance analytically.
First 36 games:
TOI/GP 15:22 (5th among regular D)
SA/60 - 28.4 (1st among regular D)
GA/60 - 1.3 (1st)
xGA/60 - 1.89 (1st)
SCA/60 - 22.95 (2nd)
HDCA/60 - 8.4 (1st)
Last 20 games:
TOI/GP - 15:58 (4th among regular D)
SA/60 - 33.23 (last among regular D)
GA/60 - 3.19 (last)
xGA/60 - 2.59 (last)
SCA/60 - 27.79 (last)
HDCA/60 - 12.2 (last)
It was literally night and day when he was used as a third pairing guy versus how he performed when he was in a second pairing role.
Or in other words, he's fine in a sheltered 3rd pairing role, but starts to get exposed when he's given top 4 minutes.