What is the reason we are moving to having 5 diamond moderators?

Question

I noticed a few days ago that our election was aiming to fill 2 moderator positions instead of just the one position that was vacated by SevenSidedDie (as I expected). Is there a reason behind that decision that the mod team would like to/is able to/is comfortable with sharing with the community as a whole?

The reason I ask is not out of idle curiosity, but because I think it often says something about the state of the community and of how the moderators are feeling which I think could be valuable to disclose to the community as a whole. And, in the past, these conversations have been held publicly on Meta.

Again, my intent is not to pry. For example, if it had something to do with the personal circumstances of a mod I certainly wouldn't want this to be pressure to reveal that. But if there's something of value to the community, I'd personally be interested to hear it.

Answer 1

There's nothing particularly magical about the number 5. A long-serving mod retired recently and we three thought that a deeper bench of experienced moderators would be good to have in the community, as other mods may choose to retire with little notice.

-doppelgreener, nitsua60, and mxyzplk

Answer 2

Unofficial Answer: We probably merit 5 moderators based on the size of the stack.

Our stack gets about 18 questions/day and about 73k visits/day.

Some other stacks for comparison:

• Super User: 217 questions/day, 711k visits/day => 9 moderators
• English Language Learners: 56 questions/day, 141k visits/day => 5 moderators
• Database Administrators: 36 questions/day, 156k visits/day => 4 moderators
• Home Improvement: 27 questions/day, 102k visits/day => 3 moderators
• Science Fiction & Fantasy: 24 questions/day, 90k visits/day => 5 moderators
• Arqade: 18 questions/day, 218k visits/day => 5 moderators
• Web Applications: 17 questions/day, 73k visits/day => 5 moderators
• Movies & TV: 13 questions/day, 79k visits/day => 3 moderators
• The Workplace: 13 questions/day, 39k visits/day => 5 moderators
• Worldbuilding: 11 questions/day, 16k visits/day => 7(!) moderators
• Seasoned Advice: 4.9 questions/day, 87k visits/day => 4 moderators
• Skeptics: 1.9 questions/day, 7.5k visits/day => 4 moderators

_{Magic links to other stacks work in comments but not in answers. My sadness knows no bounds.}

These metrics probably play at least some role in how the Stack Exchange staff decides to assign moderator slots to stacks. There are likely other metrics that are not publicly available, such as flags/day or new users/month, that also factor into whatever system they use to make these decisions.