Change default 'Blog pages show at most' to better divisible number

[thomask]

From the first versions of WordPress there is "Blog pages show at most" set to 10. It has worked fine in the old times, where the blog posts were linear. But today, they are shown in grid in default and most other templates. And very often it has a responsive behaviour - so it has 3 or 4 columns on desktop, 2 or 3 on tablets and 1 or 2 on mobile phones. The problem is, that 10 is not divisible by 3 or 4. So if you have more then default 10 posts, there is an ugly gap before the list and the numbering.

Setting this default to 12 would make it work for 99,99 % cases and it is very simple change without backward compatibility issues (as it is a database value so it will not affect existing websites, only the new ones).

[audrasjb]

Hello and thanks for this ticket,

Given that I don't think it would introduce too big risks in terms of backward compatibility, and as I agree with you that 12 would indeed be an ideal default number for most themes (works with 1, 2, 3 and 4 columns, and I don't think 5 columns is super common for blog archive), I think it would be a relevant change.

However, as far as I know theme developers (even on the WP.org repository) are allowed to programaticaly change the default setting. So while 12 appears to be the best default value for this setting, I'm not sure it is a top priority.
But worth starting to open the discussion :)

[thomask]

just for quicker solving for someone who are near git - if i am not mistaken this is "posts_per_page" settings on row 433 on ​https://github.com/WordPress/wordpress-develop/blob/a5f3087f6b5d9c52dbe67ed247165dc32427c57d/src/wp-admin/includes/schema.php#L433