The Posts screen records what happened to every post you published — how many people it went to, how many opened it, and how many read it. None of that is on the Wall, so this is the only place to find out whether an announcement landed.
Open it
Go to the group, then Posts. Each row is one post, with the reach figures as columns. Use Filter by title or content to find a specific one.
The three numbers that matter
Recipient Count — how many people the post was sent to, after visibility settings were applied. A lower number than you expected usually means Visibility options excluded a group, not that people are missing.
View Count — how many times it was opened. Opens, not people, so one person returning twice counts twice.
Percentage Seen — the share of recipients who have seen it. This is the one to judge an announcement by.
Open a post and Seen by lists the individual people, which is what you need when a specific parent says they never heard about the fixture change.
The rest of the columns
Status — Published, Scheduled or Draft. A scheduled post has no reach figures yet.
Published as and Published by — the name shown on the post, and the person who actually wrote it. They differ when Send as was used.
Published at and Created at — when it went out, and when it was written.
Groups and Recipients — where it went. No recipients means it reached nobody, which is worth investigating.
Sticky Until — the date it stops being pinned, blank if it was never sticky.
Comments and Likes — engagement counts. Comments disabled where comments were turned off.
Website — whether the post also appears on your club's public website.
Multi-group posts and Show copies
A post sent to several groups is stored as one post per group. By default the list shows you the original; Show copies reveals the per-group copies with their own reach figures.
Turn it on when you want to know which team ignored the announcement rather than how the announcement did overall. Leave it off when the totals are what you want.
What to do with a low percentage
Check whether anyone was notified. Notify recipients is off unless you switched it on — a post with no notification only reaches people who happen to open the Wall. See Create a post.
Check the visibility settings. A post restricted to Players never reached the parents.
Check for a better channel. Something time-critical is a chat message or an event invite, not a post — see How to use the chat feature in 360Player.