"Pledge" left a generally positive impression on me on first watch, while not blowing me away. Benefitting primarily from the main guest turn and the opening, but hurt a little by that there is too much familiar ground and not enough surprises which made the story feel too predictable and ordinary and a miscast. My general opinion of Season 19 was generally positive while not being blown away which is not too bad a position to be in, beginning exceptionally strongly.
On recent re-watch, my feelings are pretty much the same, well almost. There is a lot to like about "Pledge", with the standout things on first watch being the main reasons to view it (as well as 'Law and Order' completest sake). At the same time, it did feel like something was missing and that more could have been done with the premise perhaps. It is a good episode, albeit not a great one (and Season 19 did show greatness a lot) that is neither one of the best or worst.
Am going to start with the good. The photography and such as usual are fully professional, the slickness still remaining. The music is used sparingly and is haunting and non-overwrought when it is used, and it's mainly used when a crucial revelation or plot development is revealed. The direction has some nice tension while keeping things steady, without going too far the other way. The script is thought-provoking and doesn't ramble.
The story on the whole intrigues a lot and does pose some interesting questions, had no issue understanding what was going on while not finding it too easy to figure out. The opening is unusually graphic and creepy. The regulars are excellent and so is an unnerving Matt Malloy as a juicy character (that actually could have afforded to be even more developed).
However, it doesn't have enough surprises and could have done with more tension as well as attacked its subject with more edge and grit perhaps.
It also suffers from an overwrought turn from a too young Erin Dilly. Did feel that the motive was far too extreme.
Concluding, good but not great. 7/10.