Joomla Native custom fields
Since Joomla 3.7 we can add custom fields to our components. There are a LOT of options actually as you can see in the following link.
I think that it will be better to use tha Joomla function for "extra fielads" than yours. There are a lot fields that you dont have like Date and Color which are VERY helpfull to a sport site.
Thanks in advance