I saw this Viz on World War I in the Tableau forum and without a doubt, I nominated it for Viz of the Day by sending a message to public@tableau.com on 7/22. In the message, I didn't write anything but the link to the viz. On 7/25, it was selected as the Viz of the Day. Note that between 22 and 25, there was a weekend.

So, that's how good the viz is. I had nothing to add. The only concern I had was, the reference line will fall off the chart after 2018. The author Ryan Rowland replied that he will come up with a solution between now and 2018. I bet he will.

A few days ago, I felt that for an information viz, it would be really helpful to the viewers if we add some web extensions to it for people to further explore. A good viz which can only host some brief introduction after all, must serve as a springboard to more discovery on the topic. I would add a link from each battle to Google or Wikipedia, like what I did in this viz.

To my surprise, after click on the data marks, I found the links are there already in the tooltips. Ryan has thought about it already! Alas, viewers have to click or select the data marks to see the link.

Before Select
So here comes an obscure feature in Tableau regarding tooltips: Show Tooltips on Hover.
By turning it on, we can see the URL right away just by hovering, without click or select. Note that it is not the default setting. We have to turn it on manually. (Maybe I should send a request to make it the default. Or the text should be "Show URL/Link on hover"?)

Try this tweaked version to see the effect. This concludes the #TweakThursday.