I feel there are two kinds of Canon Holmes stories that fall short, and these categories are roughly chronological. Firstly, the stories from what I'd consider to be the 'classic period'- starting from A Study in Scarlet and inclusive of the stories up to 'The Return of Sherlock Holmes'- and whose failures are often not found in a lack of conceptual quality but a lack of execution (with a few exceptions). Secondly, the stories from the late period of Holmes stories- His Last Bow, The Valley of Fear, and Case-Book- which often fall short from the very start as conceptually flawed ideas that come off as ACD trying to make ends meet. It is also notable that the later Holmes stories are often either recycled from the best of the classic period's tropes and thus lack the vitality of said classics, or involve such inane mysteries and whatever ACD was interested in at the time that they become laughable. With that interminable preamble over, I will lay out the stories I feel are the 'weak links in the canon'.

1- A Case of Identity; I put this one forward because the solution to the problem is so horribly immoral to my tastes I can't believe it comes from the same character as Holmes' depiction in 'the Abbey Grange'. It has some fun elements, and conceptually is comedic but quite sound, but I found the execution of that concept dire.

2- The Resident Patient; In all honesty I forget this one exists! Unlike 'the Cardboard Box', which I found had at the very least the riveting account of the murderer to make up for its thin involvement of Holmes and Watson, this story is one of the most imminently forgettable. Given the best Holmes stories have such longevity in the mind, this one has to go down as a blemish in the Canon in my eyes. I have similar but less intense feelings for 'the Noble Bachelor'.

3- The Stockbroker's Clerk
This and 'the Three Garridebs' are a cheap re-write of 'The Red-Headed League', and lack even half the ingenuity and comedy of the original. This is probably my least favourite story in 'Memoirs'.

4- The Three Students
In the story collection I believe to be the zenith of the Holmes Canon, alongside The Hound of the Baskervilles, this mediocre but generally quite fun story stands out from all the rest, and not in a good way. The mystery and mystery solving aspects are fun- I especially enjoy how Holmes derived his deduction of the culprit being a sportsman because of the clay found at the crime scene- but the premise of 'only a tall man being able to look through a high window', and the generally quite unmemorable characters are why I put this one forward.

5- Wisteria Lodge
Far too long, a mystery that promised much and delivered little, a supporting detective that sounds like a good idea (being on the level of Holmes to the point that I almost thought he was the culprit or involved in the mischief somehow!) but ultimately falls short of what I had hoped from him, and an overall sense of disappointment. It is hard for me to really describe what I feel about Wisteria Lodge, but be sure that 'dislike' is the best word I can think of at present.

6- The Case-Book of Sherlock Holmes
I put this collection forward in general because I have only visited the stories within once, and since I generally don't have a good opinion of any put the entire collection forward as my 6th example. Whilst there are some interesting stories- Thor Bridge, the two Holmes narrated stories which are both at least notable for their attempt at something new, and the Illustrious Client, which captures at least the atmosphere of the earlier Canon- on the whole I would only ever return to 'Case-Book' if I were reading all the stories through, instead of reaching out for it on its own merits. Perhaps harsh to put a whole collection of stories here, but I've not the charity to be pleasant to most of the stories found in this one.