The problem stems from the fact line breaks are ignored in HTML by default.
There are two possible ways to fix it...
modify your HTML template to wrap your content in <pre></pre> tags - by default, those tags will honour the whitespace new lines in your content.
<b>Players On Ice:</b>
<pre>{{flow.homeOnIce}}</pre>
Add html to your content (ie <br> as you have tried), but then you must update your template to use {{{-triple-brackets-}}} - otherwise the template engine escapes HTML content: