Shulman (1986) proposed 3 core knowledge types for teacher: Pedagogy (PK), Content (CK), Pedagogical Content (PCK).
When we observe a coach we see the latter in practice. Where 'poor practice' is noticed it has been typical to point to flaws in understanding of pedagogy /1

More often than not, it (also) exposes deep flaws in the understanding of the game and creating a curriculum to learn that game (content).
Many of the discussions around skill acq concepts and theories miss this /2

For example;
You can't use TGFU if you don't understand the game you're teaching.
You can't constrain unless you understand what it is you're trying to support the emergence of
You can't instruct or explain if you don't know what you're talking about /3

You can't feedback if your analysis is poor
You can't drill if you don't know the skill you're trying hone
You can't have representative practice if you don't know what it is meant to be representative of /4

It is probably of no surprise to know that some evidence has shown that content experts support higher achievement in students - but as we would expect this is not a direct correlation. /5

Why this thread? Some of the discussions around skill acq on twitter reflect some fairly nuanced ideas that would really demand a deep understanding of the content being coached to make full use of them. Often why pedagogy reflects more than just skill acq /6

Building a knowledge of pedagogy must go hand in hand with building a knowledge of content (and I've not even spoken about the participant yet). This includes our observation of coaches. If we see a 'poor session' we must be able to get under the skin to ask why /7

This means having to go beyond questions of skill acq/pedagogy to include questions of sport understanding, breaking sport into meaningful chunks, curriculum building, matching to age and stage. /8

It needs to understand whether the PCK observed is an attempt to bring together CK and PK, or whether it just reflects a recipe take from elsewhere. If it is the latter, have we done enough to support coaches in creating their own PCK /9

Have we taught practice and task design that draw on CK and PK? Have we taught observation skills to support practice intervention? Have we taught how to decide which intervention to use and how to create meaningful verbal inputs (whether instruction, questioning or feedback) /10

Coach education is a big job. Coach development is a big job. Good education should accelerate the learning journey. But there aren't short cuts. Expert and effective coaching is bloody difficult. Creating professional development programmes to support is as well.

Shulman's work (via Berliner, 1991) was a key stimulus for this paper and schematic (with @DCGreyMattersUK & Russell Martindale.) https://www.researchgate.net/publication/7167762_The_coaching_schematic_Validation_through_expert_coach_consensus
A couple of favourite quotes from the coaches we interviewed for the study as well.