I was trying to type from my phone earlier which is always an adventure with auto correct. Long story short I tried using chrome cast and espn 3, with my laptop, and while I could view the espn 3 web page on both my lap top and tv when I clicked on a game it would only show on my laptop and there was no way for me to see the game on the tv. The two are not compatible yet. Youtube is owned by google I believe, and they cut a deal with netflix. I do not know of any other video viewing apps that are yet compatible though I admittedly I haven't tried amazon prime or any other. Espn3 Chromecast may = SOL for now. I also opened up my Watch Espn app on my droid to see if there was an option to stream via chrome cast and didn't see it. Checked for an update also and I don't see one.
If you use google chrome on a laptop there is a download or app available for the browser to make it compatible with chrome cast and that is what I used, but like I said it was useless to try and re watch the actual towson replay i was trying to watch.