"Do you think horse races have gotten faster over time, like people races?"
"We can find out!"
Heads to wikipedia. Does some fancy footwork in drive to convert units of time from M:SS.SS to seconds. Heads to plot.ly.
"Whoa, something weird happened in 1896."
"Is that when they figured out jockeys should be tiny?"
"Oh, look, they made the track shorter."
"Let's only look at times since 1896."
"So, yes, but it's leveling off?"
"Looks that way."
This data could be fun to build out for an activity to get kids using whatever scatterplot-creating tools you want them to use. It's also nice for interpreting plots -- it smacks you in the face that something changed in 1896, and there's a quick and satisfying explanation. Enjoy!